atsamd5x: add SPI.TxN()

This makes it possible to assign I2C objects (machine.I2C0,
machine.I2C1, etc.) without needing to take a pointer.

This is important especially in the future when I2C may be driven using
DMA and the machine.I2C type needs to store some state.

.circleci/config.yml

@@ -0,0 +1,396 @@
+version: 2.1
+
+commands:
+  submodules:
+    steps:
+      - run:
+          name: "Pull submodules"
+          command: git submodule update --init
+  apt-dependencies:
+    parameters:
+      llvm:
+        type: string
+    steps:
+      - run:
+          name: "Install apt dependencies"
+          command: |
+            echo 'deb https://apt.llvm.org/buster/ llvm-toolchain-buster-<<parameters.llvm>> main' | sudo tee /etc/apt/sources.list.d/llvm.list
+            wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
+            sudo apt-get update
+            sudo apt-get install \
+                llvm-<<parameters.llvm>>-dev \
+                clang-<<parameters.llvm>> \
+                libclang-<<parameters.llvm>>-dev \
+                lld-<<parameters.llvm>> \
+                gcc-arm-linux-gnueabihf \
+                gcc-aarch64-linux-gnu \
+                qemu-system-arm \
+                qemu-user \
+                gcc-avr \
+                avr-libc
+            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-8-dev
+  install-node:
+    steps:
+      - run:
+          name: "Install node.js"
+          command: |
+            wget https://nodejs.org/dist/v10.15.1/node-v10.15.1-linux-x64.tar.xz
+            sudo tar -C /usr/local -xf node-v10.15.1-linux-x64.tar.xz
+            sudo ln -s /usr/local/node-v10.15.1-linux-x64/bin/node /usr/bin/node
+            rm node-v10.15.1-linux-x64.tar.xz
+  install-chrome:
+    steps:
+      - run:
+          name: "Install Chrome"
+          command: |
+            wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
+            sudo apt install ./google-chrome-stable_current_amd64.deb
+  install-wasmtime:
+    steps:
+      - run:
+          name: "Install wasmtime"
+          command: |
+            curl https://wasmtime.dev/install.sh -sSf | bash
+            sudo ln -s ~/.wasmtime/bin/wasmtime /usr/local/bin/wasmtime
+  install-xtensa-toolchain:
+    parameters:
+      variant:
+        type: string
+    steps:
+      - run:
+          name: "Install Xtensa toolchain"
+          command: |
+            curl -L https://github.com/espressif/crosstool-NG/releases/download/esp-2020r2/xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz -o xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+            sudo tar -C /usr/local -xf xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+            sudo ln -s /usr/local/xtensa-esp32-elf/bin/xtensa-esp32-elf-ld /usr/local/bin/xtensa-esp32-elf-ld
+            rm xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+  llvm-source-linux:
+    steps:
+      - restore_cache:
+          keys:
+            - llvm-source-11-v1
+      - run:
+          name: "Fetch LLVM source"
+          command: make llvm-source
+      - save_cache:
+          key: llvm-source-11-v1
+          paths:
+            - llvm-project
+  build-wasi-libc:
+    steps:
+      - restore_cache:
+          keys:
+            - wasi-libc-sysroot-v4
+      - run:
+          name: "Build wasi-libc"
+          command: make wasi-libc
+      - save_cache:
+          key: wasi-libc-sysroot-v4
+          paths:
+            - lib/wasi-libc/sysroot
+  test-linux:
+    parameters:
+      llvm:
+        type: string
+    steps:
+      - checkout
+      - submodules
+      - apt-dependencies:
+          llvm: "<<parameters.llvm>>"
+      - install-node
+      - install-chrome
+      - install-wasmtime
+      - restore_cache:
+          keys:
+            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-v2-{{ checksum "go.mod" }}
+      - llvm-source-linux
+      - run: go install -tags=llvm<<parameters.llvm>> .
+      - restore_cache:
+          keys:
+            - wasi-libc-sysroot-systemclang-v3
+      - run: make wasi-libc
+      - save_cache:
+          key: wasi-libc-sysroot-systemclang-v3
+          paths:
+            - lib/wasi-libc/sysroot
+      - run: go test -v -tags=llvm<<parameters.llvm>> ./cgo ./compileopts ./compiler ./interp ./transform .
+      - run: make gen-device -j4
+      - run: make smoketest XTENSA=0
+      - run: make tinygo-test
+      - run: make wasmtest
+      - save_cache:
+          key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - /go/pkg/mod
+      - run: make fmt-check
+  assert-test-linux:
+    steps:
+      - checkout
+      - submodules
+      - run:
+          name: "Install apt dependencies"
+          command: |
+            sudo apt-get update
+            sudo apt-get install \
+                gcc-arm-linux-gnueabihf \
+                libc6-dev-armel-cross \
+                gcc-aarch64-linux-gnu \
+                libc6-dev-arm64-cross \
+                qemu-system-arm \
+                qemu-user \
+                gcc-avr \
+                avr-libc
+            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-6-dev
+      - install-node
+      - install-wasmtime
+      - install-xtensa-toolchain:
+          variant: "linux-amd64"
+      - restore_cache:
+          keys:
+            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-v2-{{ checksum "go.mod" }}
+      - llvm-source-linux
+      - restore_cache:
+          keys:
+            - llvm-build-11-linux-v2-assert
+      - run:
+          name: "Build LLVM"
+          command: |
+            if [ ! -f llvm-build/lib/liblldELF.a ]
+            then
+              # install dependencies
+              sudo apt-get install cmake ninja-build
+              # hack ninja to use less jobs
+              echo -e '#!/bin/sh\n/usr/bin/ninja -j3 "$@"' > /go/bin/ninja
+              chmod +x /go/bin/ninja
+              # build!
+              make ASSERT=1 llvm-build
+            fi
+      - save_cache:
+          key: llvm-build-11-linux-v2-assert
+          paths:
+            llvm-build
+      - run: make ASSERT=1
+      - build-wasi-libc
+      - run:
+          name: "Test TinyGo"
+          command: make ASSERT=1 test
+      - save_cache:
+          key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - /go/pkg/mod
+      - run: make gen-device -j4
+      - run: make smoketest TINYGO=build/tinygo
+  build-linux:
+    steps:
+      - checkout
+      - submodules
+      - run:
+          name: "Install apt dependencies"
+          command: |
+            sudo apt-get update
+            sudo apt-get install \
+                gcc-arm-linux-gnueabihf \
+                libc6-dev-armel-cross \
+                gcc-aarch64-linux-gnu \
+                libc6-dev-arm64-cross \
+                qemu-system-arm \
+                qemu-user \
+                gcc-avr \
+                avr-libc
+            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-6-dev
+      - install-node
+      - install-wasmtime
+      - install-xtensa-toolchain:
+          variant: "linux-amd64"
+      - restore_cache:
+          keys:
+            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-v2-{{ checksum "go.mod" }}
+      - llvm-source-linux
+      - restore_cache:
+          keys:
+            - llvm-build-11-linux-v2-noassert
+      - run:
+          name: "Build LLVM"
+          command: |
+            if [ ! -f llvm-build/lib/liblldELF.a ]
+            then
+              # install dependencies
+              sudo apt-get install cmake ninja-build
+              # hack ninja to use less jobs
+              echo -e '#!/bin/sh\n/usr/bin/ninja -j3 "$@"' > /go/bin/ninja
+              chmod +x /go/bin/ninja
+              # build!
+              make llvm-build
+            fi
+      - save_cache:
+          key: llvm-build-11-linux-v2-noassert
+          paths:
+            llvm-build
+      - build-wasi-libc
+      - run:
+          name: "Test TinyGo"
+          command: make test
+      - run:
+          name: "Install fpm"
+          command: |
+            sudo apt-get install ruby ruby-dev
+            sudo gem install --no-document fpm
+      - run:
+          name: "Build TinyGo release"
+          command: |
+            make release deb -j3
+            cp -p build/release.tar.gz /tmp/tinygo.linux-amd64.tar.gz
+            cp -p build/release.deb    /tmp/tinygo_amd64.deb
+      - store_artifacts:
+          path: /tmp/tinygo.linux-amd64.tar.gz
+      - store_artifacts:
+          path: /tmp/tinygo_amd64.deb
+      - save_cache:
+          key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - /go/pkg/mod
+      - run:
+          name: "Extract release tarball"
+          command: |
+            mkdir -p ~/lib
+            tar -C ~/lib -xf /tmp/tinygo.linux-amd64.tar.gz
+            ln -s ~/lib/tinygo/bin/tinygo /go/bin/tinygo
+            tinygo version
+      - run: make smoketest
+  build-macos:
+    steps:
+      - checkout
+      - submodules
+      - run:
+          name: "Install dependencies"
+          command: |
+            curl https://dl.google.com/go/go1.16.darwin-amd64.tar.gz -o go1.16.darwin-amd64.tar.gz
+            sudo tar -C /usr/local -xzf go1.16.darwin-amd64.tar.gz
+            ln -s /usr/local/go/bin/go /usr/local/bin/go
+            HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu
+      - install-xtensa-toolchain:
+          variant: "macos"
+      - restore_cache:
+          keys:
+            - go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-macos-v2-{{ checksum "go.mod" }}
+      - restore_cache:
+          keys:
+            - llvm-source-11-macos-v1
+      - run:
+          name: "Fetch LLVM source"
+          command: make llvm-source
+      - save_cache:
+          key: llvm-source-11-macos-v1
+          paths:
+            - llvm-project
+      - restore_cache:
+          keys:
+            - llvm-build-11-macos-v2
+      - run:
+          name: "Build LLVM"
+          command: |
+            if [ ! -f llvm-build/lib/liblldELF.a ]
+            then
+              # install dependencies
+              HOMEBREW_NO_AUTO_UPDATE=1 brew install cmake ninja
+              # build!
+              make llvm-build
+            fi
+      - save_cache:
+          key: llvm-build-11-macos-v2
+          paths:
+            llvm-build
+      - restore_cache:
+          keys:
+            - wasi-libc-sysroot-macos-v3
+      - run:
+          name: "Build wasi-libc"
+          command: make wasi-libc
+      - save_cache:
+          key: wasi-libc-sysroot-macos-v3
+          paths:
+            - lib/wasi-libc/sysroot
+      - run:
+          name: "Test TinyGo"
+          command: make test
+      - run:
+          name: "Build TinyGo release"
+          command: |
+            make release -j3
+            cp -p build/release.tar.gz /tmp/tinygo.darwin-amd64.tar.gz
+      - store_artifacts:
+          path: /tmp/tinygo.darwin-amd64.tar.gz
+      - run:
+          name: "Extract release tarball"
+          command: |
+            mkdir -p ~/lib
+            tar -C /usr/local/opt -xf /tmp/tinygo.darwin-amd64.tar.gz
+            ln -s /usr/local/opt/tinygo/bin/tinygo /usr/local/bin/tinygo
+            tinygo version
+      - run: make smoketest AVR=0
+      - save_cache:
+          key: go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - /go/pkg/mod
+
+jobs:
+  test-llvm10-go113:
+    docker:
+      - image: circleci/golang:1.13-buster
+    steps:
+      - test-linux:
+          llvm: "10"
+  test-llvm10-go114:
+    docker:
+      - image: circleci/golang:1.14-buster
+    steps:
+      - test-linux:
+          llvm: "10"
+  test-llvm11-go115:
+    docker:
+      - image: circleci/golang:1.15-buster
+    steps:
+      - test-linux:
+          llvm: "11"
+  test-llvm11-go116:
+    docker:
+      - image: circleci/golang:1.16-buster
+    steps:
+      - test-linux:
+          llvm: "11"
+  assert-test-linux:
+    docker:
+      - image: circleci/golang:1.14-stretch
+    steps:
+      - assert-test-linux
+  build-linux:
+    docker:
+      - image: circleci/golang:1.14-stretch
+    steps:
+      - build-linux
+  build-macos:
+    macos:
+      xcode: "10.1.0"
+    steps:
+      - build-macos
+
+
+
+workflows:
+  test-all:
+    jobs:
+      - test-llvm10-go113
+      - test-llvm10-go114
+      - test-llvm11-go115
+      - test-llvm11-go116
+      - build-linux
+      - build-macos
+      - assert-test-linux

.gitignore

@@ -3,10 +3,26 @@ docs/_build
 src/device/avr/*.go
 src/device/avr/*.ld
 src/device/avr/*.s
+src/device/esp/*.go
 src/device/nrf/*.go
 src/device/nrf/*.s
-src/device/stm32/*.go
-src/device/stm32/*.s
+src/device/nxp/*.go
+src/device/nxp/*.s
 src/device/sam/*.go
 src/device/sam/*.s
+src/device/sifive/*.go
+src/device/sifive/*.s
+src/device/stm32/*.go
+src/device/stm32/*.s
+src/device/kendryte/*.go
+src/device/kendryte/*.s
 vendor
+llvm-build
+llvm-project
+
+# Ignore files generated by smoketest
+test.gba
+test.hex
+test.nro
+test.wasm
+wasm.wasm

.gitmodules

@@ -9,8 +9,17 @@
 	url = https://github.com/avr-rust/avr-mcu.git
 [submodule "lib/cmsis-svd"]
 	path = lib/cmsis-svd
-	url = https://github.com/posborne/cmsis-svd
+	url = https://github.com/tinygo-org/cmsis-svd
 [submodule "lib/compiler-rt"]
 	path = lib/compiler-rt
 	url = https://github.com/llvm-mirror/compiler-rt.git
-	branch = release_70
+	branch = release_80
+[submodule "lib/wasi-libc"]
+	path = lib/wasi-libc
+	url = https://github.com/CraneStation/wasi-libc
+[submodule "lib/picolibc"]
+	path = lib/picolibc
+	url = https://github.com/keith-packard/picolibc.git
+[submodule "lib/stm32-svd"]
+	path = lib/stm32-svd
+	url = https://github.com/tinygo-org/stm32-svd

.travis.yml

@@ -1,33 +0,0 @@
-language: go
-
-go:
-  - "1.11"
-
-before_install:
-  - echo "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-7 main"            | sudo tee -a /etc/apt/sources.list
-  - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu trusty main" | sudo tee -a /etc/apt/sources.list
-  - sudo apt-get update -qq
-  - sudo apt-get install llvm-7-dev clang-7 libclang-7-dev binutils-arm-none-eabi qemu-system-arm --allow-unauthenticated -y
-  - sudo ln -s /usr/bin/clang-7 /usr/local/bin/cc # work around missing -no-pie in old GCC version
-
-install:
-  - curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
-  - dep ensure --vendor-only
-
-script:
-  - go install github.com/aykevl/tinygo
-  - go test -v .
-  - make gen-device
-  - tinygo build -o blinky1.nrf.elf    -target=pca10040     examples/blinky1
-  - tinygo build -o blinky2.nrf.elf    -target=pca10040     examples/blinky2
-  - tinygo build -o blinky2                                 examples/blinky2
-  - tinygo build -o test.nrf.elf       -target=pca10040     examples/test
-  - tinygo build -o blinky1.nrf51.elf  -target=microbit     examples/echo
-  - tinygo build -o test.nrf.elf       -target=nrf52840-mdk examples/blinky1
-  - tinygo build -o blinky1.nrf51d.elf -target=pca10031     examples/blinky1
-  - tinygo build -o blinky1.stm32.elf  -target=bluepill     examples/blinky1
-  - tinygo build -o blinky1.avr.o      -target=arduino      examples/blinky1 # TODO: avr-as/avr-gcc doesn't work
-  - tinygo build -o blinky1.reel.elf   -target=reelboard    examples/blinky1
-  - tinygo build -o blinky2.reel.elf   -target=reelboard    examples/blinky2
-  - tinygo build -o blinky1.pca10056.elf    -target=pca10056     examples/blinky1
-  - tinygo build -o blinky2.pca10056.elf    -target=pca10056     examples/blinky2

BUILDING.md

@@ -0,0 +1,101 @@
+# Building TinyGo
+
+TinyGo depends on LLVM and libclang, which are both big C++ libraries. It can
+also optionally use a built-in lld to ease cross compiling. There are two ways
+these can be linked: dynamically and statically. An install with `go install` is
+dynamic linking because it is fast and works almost out of the box on
+Debian-based systems with the right packages installed.
+
+This guide describes how to statically link TinyGo against LLVM, libclang and
+lld so that the binary can be easily moved between systems. It also shows how to
+build a release tarball that includes this binary and all necessary extra files.
+
+**Note**: this documentation describes how to build a statically linked release
+tarball. If you want to develop TinyGo, you will probably want to follow a
+different guide:
+
+  * [Linux](https://tinygo.org/getting-started/linux/#source-install)
+  * [macOS](https://tinygo.org/getting-started/macos/#source-install)
+  * [Windows](https://tinygo.org/getting-started/windows/#source-install)
+
+## Dependencies
+
+LLVM, Clang and LLD are quite light on dependencies, requiring only standard
+build tools to be built. Go is of course necessary to build TinyGo itself.
+
+  * Go (1.13+)
+  * Standard build tools (gcc/clang)
+  * git
+  * CMake
+  * [Ninja](https://ninja-build.org/)
+
+The rest of this guide assumes you're running Linux, but it should be equivalent
+on a different system like Mac.
+
+## Download the source
+
+The first step is to download the TinyGo sources (use `--recursive` if you clone
+the git repository). Then, inside the directory, download the LLVM source:
+
+    make llvm-source
+
+You can also store LLVM outside of the TinyGo root directory by setting the
+`LLVM_BUILDDIR`, `CLANG_SRC` and `LLD_SRC` make variables, but that is not
+covered by this guide.
+
+## Build LLVM, Clang, LLD
+
+Before starting the build, you may want to set the following environment
+variables to speed up the build. Most Linux distributions ship with GCC as the
+default compiler, but Clang is significantly faster and uses much less memory
+while producing binaries that are about as fast.
+
+    export CC=clang
+    export CXX=clang++
+
+The Makefile includes a default configuration that is good for most users. It
+builds a release version of LLVM (optimized, no asserts) and includes all
+targets supported by TinyGo:
+
+    make llvm-build
+
+This can take over an hour depending on the speed of your system.
+
+## Build TinyGo
+
+The last step of course is to build TinyGo itself. This can again be done with
+make:
+
+    make
+
+## Verify TinyGo
+
+Try running TinyGo:
+
+    ./build/tinygo help
+
+Also, make sure the `tinygo` binary really is statically linked. Check this
+using `ldd` (not to be confused with `lld`):
+
+    ldd ./build/tinygo
+
+The result should not contain libclang or libLLVM.
+
+## Make a release tarball
+
+Now that we have a working static build, it's time to make a release tarball:
+
+    make release
+
+If you did not clone the repository with the `--recursive` option, you will get errors until you initialize the project submodules:
+
+    git submodule update --init
+
+The release tarball is stored in build/release.tar.gz, and can be extracted with
+the following command (for example in ~/lib):
+
+    tar -xvf path/to/release.tar.gz
+
+TinyGo will get extracted to a `tinygo` directory. You can then call it with:
+
+    ./tinygo/bin/tinygo

CHANGELOG.md

@@ -0,0 +1,836 @@
+0.17.0
+
+---
+* **command line**
+  - switch to LLVM 11 for static builds
+  - support gdb debugging with AVR
+  - add support for additional openocd commands
+  - add `-x` flag to print commands
+  - use LLVM 11 by default when linking LLVM dynamically
+  - update go-llvm to use LLVM 11 on macOS
+  - bump go.bug.st/serial to version 1.1.2
+  - do not build LLVM with libxml to work around a bugo on macOS
+  - add support for Go 1.16
+  - support gdb daemonization on Windows
+  - remove support for LLVM 9, to fix CI
+  - kill OpenOCD if it does not exit with a regular quit signal
+  - support `-ocd-output` on Windows
+* **compiler**
+  - `builder`: parallelize most of the build
+  - `builder`: remove unused cacheKey parameter
+  - `builder`: add -mcpu flag while building libraries
+  - `builder`: wait for running jobs to finish
+  - `cgo`: add support for variadic functions
+  - `compiler`: fix undefined behavior in wordpack
+  - `compiler`: fix incorrect "exported function" panic
+  - `compiler`: fix non-int integer constants (fixing a crash)
+  - `compiler`: refactor and add tests
+  - `compiler`: emit a nil check when slicing an array pointer
+  - `compiler`: saturate float-to-int conversions
+  - `compiler`: test float to int conversions and fix upper-bound calculation
+  - `compiler`: support all kinds of deferred builtins
+  - `compiler`: remove ir package
+  - `compiler`: remove unnecessary main.main call workaround
+  - `compiler`: move the setting of attributes to getFunction
+  - `compiler`: create runtime types lazily when needed
+  - `compiler`: move settings to a separate Config struct
+  - `compiler`: work around an ARM backend bug in LLVM
+  - `interp`: rewrite entire package
+  - `interp`: fix alignment of untyped globals
+  - `loader`: use name "main" for the main package
+  - `loader`: support imports from vendor directories
+  - `stacksize`: add support for DW_CFA_offset_extended
+  - `transform`: show better error message in coroutines lowering
+* **standard library**
+  - `machine`: accept configuration struct for ADC parameters
+  - `machine`: make I2C.Configure signature consistent
+  - `reflect`: implement PtrTo
+  - `runtime`: refactor to simplify stack switching
+  - `runtime`: put metadata at the top end of the heap
+* **targets**
+  - `atsam`: add a length check to findPinPadMapping
+  - `atsam`: improve USBCDC
+  - `atsam`: avoid infinite loop when USBCDC is disconnected
+  - `avr`: add SPI support for Atmega based chips
+  - `avr`: use Clang for compiling C and assembly files
+  - `esp32`: implement task based scheduler
+  - `esp32`: enable the FPU
+  - `esp8266`: implement task based scheduler
+  - `esp`: add compiler-rt library
+  - `esp`: add picolibc
+  - `nrf`: refactor code a bit to reduce duplication
+  - `nrf`: use SPIM peripheral instead of the legacy SPI peripheral
+  - `nrf`: update nrfx submodule to latest commit
+  - `nrf52840`: ensure that USB CDC interface is only initialized once
+  - `nrf52840`: improve USBCDC
+  - `stm32`: use stm32-rs SVDs which are of much higher quality
+  - `stm32`: harmonization of UART logic
+  - `stm32`: replace I2C addressable interface with simpler type
+  - `stm32`: fix i2c and add stm32f407 i2c
+  - `stm32`: revert change that adds support for channels in interrupts
+  - `wasm`: implement a growable heap
+  - `wasm`: fix typo in wasm_exec.js, syscall/js.valueLoadString()
+  - `wasm`: Namespaced Wasm Imports so they don't conflict across modules, or reserved LLVM IR
+  - `wasi`: support env variables based on libc
+  - `wasi`: specify wasi-libc in a different way, to improve error message
+* **boards**
+  - `matrixportal-m4`: add support for board Adafruit Matrix Portal M4
+  - `mkr1000`: add this board
+  - `nucleo-f722ze`: add this board
+  - `clue`: correct volume name and add alias for release version of Adafruit Clue board
+  - `p1am-100`: add support for the P1AM-100 (similar to Arduino MKR)
+  - `microbit-v2`: add initial support based on work done by @alankrantas thank you!
+  - `lgt92`: support for STM32L0 MCUs and Dragino LGT92 device
+  - `nicenano`: nice!nano board support
+  - `circuitplay-bluefruit`: correct internal I2C pin mapping
+  - `clue`: correct for lack of low frequency crystal
+  - `digispark`: split off attiny85 target
+  - `nucleo-l552ze`: implementation with CLOCK, LED, and UART
+  - `nrf52840-mdk-usb-dongle`: add this board
+
+0.16.0
+---
+
+* **command-line**
+  - add initial support for LLVM 11
+  - make lib64 clang include path check more robust
+  - `build`: improve support for GOARCH=386 and add tests
+  - `gdb`: add support for qemu-user targets
+  - `test`: support non-host tests
+  - `test`: add support for -c and -o flags
+  - `test`: implement some benchmark stubs
+* **compiler**
+  - `builder`: improve detection of clang on Fedora
+  - `compiler`: fix floating point comparison bugs
+  - `compiler`: implement negate for complex numbers
+  - `loader`: fix linkname in test binaries
+  - `transform`: add missing return pointer restore for regular coroutine tail
+    calls
+* **standard library**
+  - `machine`: switch default frequency to 4MHz
+  - `machine`: clarify caller's responsibility in `SetInterrupt`
+  - `os`: add `LookupEnv()` stub
+  - `reflect`: implement `Swapper`
+  - `runtime`: fix UTF-8 decoding
+  - `runtime`: gc: use raw stack access whenever possible
+  - `runtime`: use dedicated printfloat32
+  - `runtime`: allow ranging over a nil map
+  - `runtime`: avoid device/nxp dependency in HardFault handler
+  - `testing`: implement dummy Helper method
+  - `testing`: add Run method
+* **targets**
+  - `arm64`: add support for SVCall intrinsic
+  - `atsamd51`: avoid panic when configuring SPI with SDI=NoPin
+  - `avr`: properly support the `.rodata` section
+  - `esp8266`: implement `Pin.Get` function
+  - `nintendoswitch`: fix crash when printing long lines (> 120)
+  - `nintendoswitch`: add env parser and removed unused stuff
+  - `nrf`: add I2C error checking
+  - `nrf`: give more flexibility in picking SPI speeds
+  - `nrf`: fix nrf52832 flash size
+  - `stm32f103`: support wakeups from interrupts
+  - `stm32f405`: add SPI support
+  - `stm32f405`: add I2C support
+  - `wasi`: add support for this target
+  - `wasi`: use 'generic' ABI by default
+  - `wasi`: remove --no-threads flag from wasm-ld
+  - `wasm`: add instanceof support for WebAssembly
+  - `wasm`: use fixed length buffer for putchar
+* **boards**
+  - `d1mini`: add this ESP8266 based board
+  - `esp32`: use board definitions instead of chip names
+  - `qtpy`: add board definition for Adafruit QTPy
+  - `teensy40`: add this board
+
+0.15.0
+---
+
+* **command-line**
+  - add cached GOROOT to info subcommand
+  - embed git-hash in tinygo-dev executable
+  - implement tinygo targets to list usable targets
+  - use simpler file copy instead of file renaming to avoid issues on nrf52840 UF2 bootloaders
+  - use ToSlash() to specify program path
+  - support flashing esp32/esp8266 directly from tinygo
+  - when flashing call PortReset only on other than openocd
+* **compiler**
+  - `compileopts`: add support for custom binary formats
+  - `compiler`: improve display of goroutine wrappers
+  - `interp`: don't panic in the Store method
+  - `interp`: replace some panics with error messages
+  - `interp`: show error line in first line of the traceback
+  - `loader`: be more robust when creating the cached GOROOT
+  - `loader`: rewrite/refactor much of the code to use go list directly
+  - `loader`: use ioutil.TempDir to create a temporary directory
+  - `stacksize`: deal with DW_CFA_advance_loc1
+* **standard library**
+  - `runtime`: use waitForEvents when appropriate
+* **wasm**
+  - `wasm`: Remove --no-threads from wasm-ld calls.
+  - `wasm`: update wasi-libc dependency
+* **targets**
+  - `arduino-mega2560`: fix flashing on Windows
+  - `arm`: automatically determine stack sizes
+  - `arm64`: make dynamic loader structs and constants private
+  - `avr`: configure emulator in board files
+  - `cortexm`: fix stack size calculation with interrupts
+  - `flash`: add openocd settings to atsamd21 / atsamd51
+  - `flash`: add openocd settings to nrf5
+  - `microbit`: reelboard: flash using OpenOCD when needed
+  - `nintendoswitch`: Add dynamic loader for runtime loading PIE sections
+  - `nintendoswitch`: fix import cycle on dynamic_arm64.go
+  - `nintendoswitch`: Fix invalid memory read / write in print calls
+  - `nintendoswitch`: simplified assembly code
+  - `nintendoswitch`: support outputting .nro files directly
+* **boards**
+  - `arduino-zero`: Adding support for the Arduino Zero (#1365)
+  - `atsamd2x`: fix BAUD value
+  - `atsamd5x`: fix BAUD value
+  - `bluepill`: Enable stm32's USART2 for the board and map it to UART1 tinygo's device
+  - `device/atsamd51x`: add all remaining bitfield values for PCHCTRLm Mapping
+  - `esp32`: add libgcc ROM functions to linker script
+  - `esp32`: add SPI support
+  - `esp32`: add support for basic GPIO
+  - `esp32`: add support for the Espressif ESP32 chip
+  - `esp32`: configure the I/O matrix for GPIO pins
+  - `esp32`: export machine.PortMask* for bitbanging implementations
+  - `esp8266`: add support for this chip
+  - `machine/atsamd51x,runtime/atsamd51x`: fixes needed for full support for all PWM pins. Also adds some useful constants to clarify peripheral clock usage
+  - `machine/itsybitsy-nrf52840`: add support for Adafruit Itsybitsy nrf52840 (#1243)
+  - `machine/stm32f4`: refactor common code and add new build tag stm32f4 (#1332)
+  - `nrf`: add SoftDevice support for the Circuit Playground Bluefruit
+  - `nrf`: call sd_app_evt_wait when the SoftDevice is enabled
+  - `nrf52840`: add build tags for SoftDevice support
+  - `nrf52840`: use higher priority for USB-CDC code
+  - `runtime/atsamd51x`: use PCHCTRL_GCLK_SERCOMX_SLOW for setting clocks on all SERCOM ports
+  - `stm32f405`: add basic UART handler
+  - `stm32f405`: add STM32F405 machine/runtime, and new board/target feather-stm32f405
+* **build**
+  - `all`: run test binaries in the correct directory
+  - `build`: Fix arch release job
+  - `ci`: run `tinygo test` for known-working packages
+  - `ci`: set git-fetch-depth to 1
+  - `docker`: fix the problem with the wasm build (#1357)
+  - `Makefile`: check whether submodules have been downloaded in some common cases
+* **docs**
+  - add ESP32, ESP8266, and Adafruit Feather STM32F405 to list of supported boards
+
+0.14.1
+---
+* **command-line**
+  - support for Go 1.15
+* **compiler**
+  - loader:  work around Windows symlink limitation
+
+0.14.0
+---
+* **command-line**
+  - fix `getDefaultPort()` on non-English Windows locales
+  - compileopts: improve error reporting of unsupported flags
+  - fix test subcommand
+  - use auto-retry to locate MSD for UF2 and HEX flashing
+  - fix touchSerialPortAt1200bps on Windows
+  - support package names with backslashes on Windows
+* **compiler**
+  - fix a few crashes due to named types
+  - add support for atomic operations
+  - move the channel blocked list onto the stack
+  - fix -gc=none
+  - fix named string to `[]byte` slice conversion
+  - implement func value and builtin defers
+  - add proper parameter names to runtime.initAll, to fix a panic
+  - builder: fix picolibc include path
+  - builder: use newer version of gohex
+  - builder: try to determine stack size information at compile time
+  - builder: remove -opt=0
+  - interp: fix sync/atomic.Value load/store methods
+  - loader: add Go module support
+  - transform: fix debug information in func lowering pass
+  - transform: do not special-case zero or one implementations of a method call
+  - transform: introduce check for method calls on nil interfaces
+  - transform: gc: track 0-index GEPs to fix miscompilation
+* **cgo**
+  - Add LDFlags support
+* **standard library**
+  - extend stdlib to allow import of more packages
+  - replace master/slave terminology with appropriate alternatives (MOSI->SDO
+    etc)
+  - `internal/bytealg`: reimplement bytealg in pure Go
+  - `internal/task`: fix nil panic in (*internal/task.Stack).Pop
+  - `os`: add Args and stub it with mock data
+  - `os`: implement virtual filesystem support
+  - `reflect`: add Cap and Len support for map and chan
+  - `runtime`: fix return address in scheduler on RISC-V
+  - `runtime`: avoid recursion in printuint64 function
+  - `runtime`: replace ReadRegister with AsmFull inline assembly
+  - `runtime`: fix compilation errors when using gc.extalloc
+  - `runtime`: add cap and len support for chans
+  - `runtime`: refactor time handling (improving accuracy)
+  - `runtime`: make channels work in interrupts
+  - `runtime/interrupt`: add cross-chip disable/restore interrupt support
+  - `sync`: implement `sync.Cond`
+  - `sync`: add WaitGroup
+* **targets**
+  - `arm`: allow nesting in DisableInterrupts and EnableInterrupts
+  - `arm`: make FPU configuraton consistent
+  - `arm`: do not mask fault handlers in critical sections
+  - `atmega2560`: fix pin mapping for pins D2, D5 and the L port
+  - `atsamd`: return an error when an incorrect PWM pin is used
+  - `atsamd`: add support for pin change interrupts
+  - `atsamd`: add DAC support
+  - `atsamd21`: add more ADC pins
+  - `atsamd51`: fix ROM / RAM size on atsamd51j20
+  - `atsamd51`: add more pins
+  - `atsamd51`: add more ADC pins
+  - `atsamd51`: add pin change interrupt settings
+  - `atsamd51`: extend pinPadMapping
+  - `arduino-nano33`: use (U)SB flag to ensure that device can be found when
+     not on default port
+  - `arduino-nano33`: remove (d)ebug flag to reduce console noise when flashing
+  - `avr`: use standard pin numbering
+  - `avr`: unify GPIO pin/port code
+  - `avr`: add support for PinInputPullup
+  - `avr`: work around codegen bug in LLVM 10
+  - `avr`: fix target triple
+  - `fe310`: remove extra println left in by mistake
+  - `feather-nrf52840`: add support for the Feather nRF52840
+  - `maixbit`: add board definition and dummy runtime
+  - `nintendoswitch`: Add experimental Nintendo Switch support without CRT
+  - `nrf`: expose the RAM base address
+  - `nrf`: add support for pin change interrupts
+  - `nrf`: add microbit-s110v8 target
+  - `nrf`: fix bug in SPI.Tx
+  - `nrf`: support debugging the PCA10056
+  - `pygamer`: add Adafruit PyGamer suport
+  - `riscv`: fix interrupt configuration bug
+  - `riscv`: disable linker relaxations during gp init
+  - `stm32f4disco`: add new target with ST-Link v2.1 debugger
+  - `teensy36`: add Teensy 3.6 support
+  - `wasm`: fix event handling
+  - `wasm`: add --no-demangle linker option
+  - `wioterminal`: add support for the Seeed Wio Terminal
+  - `xiao`: add support for the Seeed XIAO
+
+0.13.1
+---
+* **standard library**
+  - `runtime`: do not put scheduler and GC code in the same section
+  - `runtime`: copy stack scan assembly for GBA
+* **boards**
+  - `gameboy-advance`: always use ARM mode instead of Thumb mode
+
+
+0.13.0
+---
+* **command line**
+  - use `gdb-multiarch` for debugging Cortex-M chips
+  - support `tinygo run` with simavr
+  - support LLVM 10
+  - support Go 1.14
+  - retry 3 times when attempting to do a 1200-baud reset
+* **compiler**
+  - mark the `abort` function as noreturn
+  - fix deferred calls to exported functions
+  - add debug info for local variables
+  - check for channel size limit
+  - refactor coroutine lowering
+  - add `dereferenceable_or_null` attribute to pointer parameters
+  - do not perform nil checking when indexing slices and on `unsafe.Pointer`
+  - remove `runtime.isnil` hack
+  - use LLVM builtins for runtime `memcpy`/`memmove`/`memzero` functions
+  - implement spec-compliant shifts on negative/overflow
+  - support anonymous type asserts
+  - track pointer result of string concatenation for GC
+  - track PHI nodes for GC
+  - add debug info to goroutine start wrappers
+  - optimize comparing interface values against nil
+  - fix miscompilation when deferring an interface call
+  - builder: include picolibc for most baremetal targets
+  - builder: run tools (clang, lld) as separate processes
+  - builder: use `-fshort-enums` consistently
+  - interp: add support for constant type asserts
+  - interp: better support for interface operations
+  - interp: include backtrace with error
+  - transform: do not track const globals for GC
+  - transform: replace panics with source locations
+  - transform: fix error in interface lowering pass
+  - transform: make coroutine lowering deterministic
+  - transform: fix miscompilation in func lowering
+* **cgo**
+  - make `-I` and `-L` paths absolute
+* **standard library**
+  - `machine`: set the USB VID and PID to the manufacturer values
+  - `machine`: correct USB CDC composite descriptors
+  - `machine`: move `errors.New` calls to globals
+  - `runtime`: support operations on nil maps
+  - `runtime`: fix copy builtin return value on AVR
+  - `runtime`: refactor goroutines
+  - `runtime`: support `-scheduler=none` on most platforms
+  - `runtime`: run package initialization in the main goroutine
+  - `runtime`: export `malloc` / `free` for use from C
+  - `runtime`: add garbage collector that uses an external allocator
+  - `runtime`: scan callee-saved registers while marking the stack
+  - `runtime`: remove recursion from conservative GC
+  - `runtime`: fix blocking select on nil channel
+  - `runtime/volatile`: include `ReplaceBits` method
+  - `sync`: implement trivial `sync.Map`
+* **targets**
+  - `arm`: use `-fomit-frame-pointer`
+  - `atmega1284`: support this chip for testing purposes
+  - `atsamd51`: make QSPI available on all boards
+  - `atsamd51`: add support for ADC1
+  - `atsamd51`: use new interrupt registration in UART code
+  - `attiny`: clean up pin definitions
+  - `avr`: use the correct RAM start address
+  - `avr`: pass the correct `-mmcu` flag to the linker
+  - `avr`: add support for tasks scheduler (disabled by default)
+  - `avr`: fix linker problem with overlapping program/data areas
+  - `nrf`: fix typo in pin configuration options
+  - `nrf`: add lib/nrfx/mdk to include dirs
+  - `nrf52840`: implement USB-CDC
+  - `riscv`: implement VirtIO target and add RISC-V integration test
+  - `riscv`: add I2C support for the HiFive1 rev B board
+  - `stm32`: refactor GPIO pin handling
+  - `stm32`: refactor UART code
+  - `stm32f4`: add SPI
+  - `wasm`: support Go 1.14 (breaking previous versions)
+  - `wasm`: support `syscall/js.CopyBytesToJS`
+  - `wasm`: sync polyfills from Go 1.14.
+* **boards**
+  - `arduino-mega2560`: add the Arduino Mega 2560
+  - `clue-alpha`: add the Adafruit CLUE Alpha
+  - `gameboy-advance`: enable debugging with GDB
+  - `particle-argon`: add the Particle Argon board
+  - `particle-boron`: add the Particle Boron board
+  - `particle-xenon`: add the Particle Xenon board
+  - `reelboard`: add `reelboard-s140v7` SoftDevice target
+
+0.12.0
+---
+* **command line**
+  - add initial FreeBSD support
+  - remove getting a serial port in gdb subcommand
+  - add support for debugging through JLinkGDBServer
+  - fix CGo when cross compiling
+  - remove default port check for Digispark as micronucleus communicates directly using HID
+  - differentiate between various serial/USB error messages
+* **builder**
+  - improve detection of Clang headers
+* **compiler**
+  - fix assertion on empty interface
+  - don't crash when encountering `types.Invalid`
+  - revise defer to use heap allocations when running a variable number of times
+  - improve error messages for failed imports
+  - improve "function redeclared" error
+  - add globaldce pass to start of optimization pipeline
+  - add support for debugging globals
+  - implement RISC-V CSR operations as intrinsics
+  - add support for CGO_ENABLED environment variable
+  - do not emit debug info for extern globals (bugfix)
+  - add support for interrupts
+  - implement maps for arbitrary keys
+  - interp: error location for "unknown GEP" error
+  - wasm-abi: create temporary allocas in the entry block
+* **cgo**
+  - add support for symbols in `#define`
+  - fix a bug in number tokenization
+* **standard library**
+  - `machine`: avoid bytes package in USB logic
+  - `runtime`: fix external address declarations
+  - `runtime`: provide implementation for `internal/bytealg.IndexByte`
+* **targets**
+  - `atsamd51`: fix volatile usage
+  - `atsamd51`: fix ADC, updating to 12-bits precision
+  - `atsamd51`: refactor SPI pin configuration to only look at pin numbers
+  - `atsamd51`: switch UART to use new pin configuration
+  - `atsamd51`: fix obvious bug in I2C code
+  - `atsamd51`: use only the necessary UART interrupts
+  - `atsamd51`: refactor I2C pin handling to auto-detect pin mode
+  - `avr`: use a garbage collector
+  - `fe310`: use CLINT peripheral for timekeeping
+  - `fe310`: add support for PLIC interrupts
+  - `fe310`: implement UART receive interrupts
+  - `riscv`: support sleeping in QEMU
+  - `riscv`: add bare-bones interrupt support
+  - `riscv`: print exception PC and code
+  - `wasm`: implement memcpy and memset
+  - `wasm`: include wasi-libc
+  - `wasm`: use wasi ABI for basic startup/stdout
+* **boards**
+  - `arduino`: make avrdude command line compatible with Windows
+  - `arduino-nano`: add this board
+  - `arduino-nano33`: fix UART1 and UART2
+  - `circuitplay-bluefruit`: add this board
+  - `digispark`: add clock speed and pin mappings
+  - `gameboy-advance`: include compiler-rt in build
+  - `gameboy-advance`: implement interrupt handler
+  - `hifive1b`: add support for gdb subcommand
+  - `pyportal`: add this board
+  - `pyportal`: remove manual SPI pin mapping as now handled by default
+
+
+0.11.0
+---
+* **command line**
+  - add support for QEMU in `gdb` subcommand
+  - use builtin Clang when building statically, dropping the clang-9 dependency
+  - search for default serial port on both macOS and Linux
+  - windows: support `tinygo flash` directly by using win32 wmi
+* **compiler**
+  - add location information to the IR checker
+  - make reflection sidetables constant globals
+  - improve error locations in goroutine lowering
+  - interp: improve support for maps with string keys
+  - interp: add runtime fallback for mapassign operations
+* **standard library**
+  - `machine`: add support for `SPI.Tx()` on play.tinygo.org
+  - `machine`: rename `CPU_FREQUENCY` to `CPUFrequency()`
+* **targets**
+  - `adafruit-pybadge`: add Adafruit Pybadge
+  - `arduino-nano33`: allow simulation on play.tinygo.org
+  - `arduino-nano33`: fix default SPI pin numbers to be D13/D11/D12
+  - `circuitplay-express`: allow simulation on play.tinygo.org
+  - `hifive1-qemu`: add target for testing RISC-V bare metal in QEMU
+  - `riscv`: fix heap corruption due to changes in LLVM 9
+  - `riscv`: add support for compiler-rt
+  - `qemu`: rename to `cortex-m-qemu`
+
+0.10.0
+---
+* **command line**
+  - halt GDB after flashing with `gdb` subcommand
+  - fix a crash when using `-ocd-output`
+  - add `info` subcommand
+  - add `-programmer` flag
+* **builder**
+  - macos: use llvm@8 instead of just llvm in paths
+  - add `linkerscript` key to target JSON files
+  - write a symbol table when writing out the compiler-rt lib
+  - make Clang header detection more robust
+  - switch to LLVM 9
+* **compiler**
+  - fix interface miscompilation with reflect
+  - fix miscompile of static goroutine calls to closures
+  - fix `todo: store` panic
+  - fix incorrect starting value for optimized allocations in a loop
+  - optimize coroutines on non-Cortex-M targets
+  - fix crash for programs which have heap allocations but never hit the GC
+  - add support for async interface calls
+  - fix inserting non-const values in a const global
+  - interp: improve error reporting
+  - interp: implement comparing ptrtoint to 0
+* **cgo**
+  - improve diagnostics
+  - implement the constant parser (for `#define`) as a real parser
+  - rename reserved field names such as `type`
+  - avoid `"unsafe" imported but not used` error
+  - include all enums in the CGo Go AST
+  - add support for nested structs and unions
+  - implement `#cgo CFLAGS`
+* **standard library**
+  - `reflect`: add implementation of array alignment
+  - `runtime`: improve scheduler performance when no goroutines are queued
+  - `runtime`: add blocking select
+  - `runtime`: implement interface equality in non-trivial cases
+  - `runtime`: add AdjustTimeOffset to update current time
+  - `runtime`: only implement CountString for required platforms
+  - `runtime`: use MSP/PSP registers for scheduling on Cortex-M
+* **targets**
+  - `arm`: add system timer registers
+  - `atmega`: add port C GPIO support
+  - `atsamd21`: correct handling of pins >= 32
+  - `atsamd21`: i2s initialization fixes
+  - `atsamd51`: fix clock init code
+  - `atsamd51`: correct initialization for RTC
+  - `atsamd51`: fix pin function selection
+  - `atsamd51`: pin method cleanup
+  - `atsamd51`: allow setting pin mode for each of the SPI pins
+  - `atsamd51`: correct channel init and pin map for ADC based on ItsyBitsy-M4
+  - `feather-m4`: add Adafruit Feather M4 board
+  - `hifive1b`: add support for SPI1
+  - `hifive1b`: fix compiling in simulation
+  - `linux`: fix time on arm32
+  - `metro-m4`: add support for Adafruit Metro M4 Express Airlift board
+  - `metro-m4`: fixes for UART2
+  - `pinetime-devkit0`: add support for the PineTime dev kit
+  - `x9pro`: add support for this smartwatch
+  - `pca10040-s132v6`: add support for SoftDevice
+  - `pca10056-s140v7`: add support for SoftDevice
+  - `arduino-nano33`: added SPI1 connected to NINA-W102 chip on Arduino Nano 33 IOT
+
+0.9.0
+---
+* **command line**
+  - implement 1200-baud UART bootloader reset when flashing boards that support
+    it
+  - flash using mass-storage device for boards that support it
+  - implement `tinygo env`
+  - add support for Windows (but not yet producing Windows binaries)
+  - add Go version to `tinygo env`
+  - update SVD files for up-to-date peripheral interfaces
+* **compiler**
+  - add `//go:align` pragma
+  - fix bug related to type aliases
+  - add support for buffered channels
+  - remove incorrect reflect optimization
+  - implement copying slices in init interpretation
+  - add support for constant indices with a named type
+  - add support for recursive types like linked lists
+  - fix miscompile of function nil panics
+  - fix bug related to goroutines
+* **standard library**
+  - `machine`: do not check for nil slices in `SPI.Tx`
+  - `reflectlite`: add support for Go 1.13
+  - `runtime`: implement `internal/bytealg.CountString`
+  - `sync`: properly handle nil `New` func in `sync.Pool`
+* **targets**
+  - `arduino`: fix .bss section initialization
+  - `fe310`: implement `Pin.Get`
+  - `gameboy-advance`: support directly outputting .gba files
+  - `samd`: reduce code size by avoiding reflection
+  - `samd21`: do not hardcode pin numbers for peripherals
+  - `stm32f103`: avoid issue with `time.Sleep` less than 200µs
+
+0.8.0
+---
+* **command line**
+  - fix parsing of beta Go versions
+  - check the major/minor installed version of Go before compiling
+  - validate `-target` flag better to not panic on an invalid target
+* **compiler**
+  - implement full slice expression: `s[:2:4]`
+  - fix a crash when storing a linked list in an interface
+  - fix comparing struct types by making type IDs more unique
+  - fix some bugs in IR generation
+  - add support for linked lists in reflect data
+  - implement `[]rune` to string conversion
+  - implement support for `go` on func values
+* **standard library**
+  - `reflect`: add support for named types
+  - `reflect`: add support for `t.Bits()`
+  - `reflect`: add basic support for `t.AssignableTo()`
+  - `reflect`: implement `t.Align()`
+  - `reflect`: add support for struct types
+  - `reflect`: fix bug in `v.IsNil` and `v.Pointer` for addressable values
+  - `reflect`: implement support for array types
+  - `reflect`: implement `t.Comparable()`
+  - `runtime`: implement stack-based scheduler
+  - `runtime`: fix bug in the sleep queue of the scheduler
+  - `runtime`: implement `memcpy` for Cortex-M
+  - `testing`: implement stub `testing.B` struct
+  - `testing`: add common test logging methods such as Errorf/Fatalf/Printf
+* **targets**
+  - `386`: add support for linux/386 syscalls
+  - `atsamd21`: make SPI pins configurable so that multiple SPI ports can be
+    used
+  - `atsamd21`: correct issue with invalid first reading coming from ADC
+  - `atsamd21`: add support for reset-to-bootloader using 1200baud over USB-CDC
+  - `atsamd21`: make pin selection more flexible for peripherals
+  - `atsamd21`: fix minimum delay in `time.Sleep`
+  - `atsamd51`: fix minimum delay in `time.Sleep`
+  - `nrf`: improve SPI write-only speed, by making use of double buffering
+  - `stm32f103`: fix SPI frequency selection
+  - `stm32f103`: add machine.Pin.Get method for reading GPIO values
+  - `stm32f103`: allow board specific UART usage
+  - `nucleo-f103rb`: add support for NUCLEO-F103RB board
+  - `itsybitsy-m4`: add support for this board with a SAMD51 family chip
+  - `cortex-m`: add support for `arm.SystemReset()`
+  - `gameboy-advance`: add initial support for the GameBoy Advance
+  - `wasm`: add `//go:wasm-module` magic comment to set the wasm module name
+  - `wasm`: add syscall/js.valueSetIndex support
+  - `wasm`: add syscall/js.valueInvoke support
+
+0.7.1
+---
+* **targets**
+  - `atsamd21`: add support for the `-port` flag in the flash subcommand
+
+0.7.0
+---
+* **command line**
+  - try more locations to find Clang built-in headers
+  - add support for `tinygo test`
+  - build current directory if no package is specified
+  - support custom .json target spec with `-target` flag
+  - use zversion.go to detect version of GOROOT version
+  - make initial heap size configurable for some targets (currently WebAssembly
+    only)
+* **cgo**
+  - add support for bitfields using generated getters and setters
+  - add support for anonymous structs
+* **compiler**
+  - show an error instead of panicking on duplicate function definitions
+  - allow packages like github.com/tinygo-org/tinygo/src/\* by aliasing it
+  - remove `//go:volatile` support  
+    It has been replaced with the runtime/volatile package.
+  - allow poiners in map keys
+  - support non-constant syscall numbers
+  - implement non-blocking selects
+  - add support for the `-tags` flag
+  - add support for `string` to `[]rune` conversion
+  - implement a portable conservative garbage collector (with support for wasm)
+  - add the `//go:noinline` pragma
+* **standard library**
+  - `os`: add `os.Exit` and `syscall.Exit`
+  - `os`: add several stubs
+  - `runtime`: fix heap corruption in conservative GC
+  - `runtime`: add support for math intrinsics where supported, massively
+    speeding up some benchmarks
+  - `testing`: add basic support for testing
+* **targets**
+  - add support for a generic target that calls `__tinygo_*` functions for
+    peripheral access
+  - `arduino-nano33`: add support for this board
+  - `hifive1`: add support for this RISC-V board
+  - `reelboard`: add e-paper pins
+  - `reelboard`: add `PowerSupplyActive` to enable voltage for on-board devices
+  - `wasm`: put the stack at the start of linear memory, to detect stack
+    overflows
+
+0.6.0
+---
+* **command line**
+  - some portability improvements
+  - make `$GOROOT` more robust and configurable
+  - check for Clang at the Homebrew install location as fallback
+* **compiler driver**
+  - support multiple variations of LLVM commands, for non-Debian distributions
+* **compiler**
+  - improve code quality in multiple ways
+  - make panic configurable, adding trap on panic
+  - refactor many internal parts of the compiler
+  - print all errors encountered during compilation
+  - implement calling function values of a named type
+  - implement returning values from blocking functions
+  - allow larger-than-int values to be sent across a channel
+  - implement complex arithmetic
+  - improve hashmap support
+  - add debuginfo for function arguments
+  - insert nil checks on stores (increasing code size)
+  - implement volatile operations as compiler builtins
+  - add `//go:inline` pragma
+  - add build tags for the Go stdlib version
+* **cgo**
+  - implement `char`, `enum` and `void*` types
+  - support `#include` for builtin headers
+  - improve typedef/struct/enum support
+  - only include symbols that are necessary, for broader support
+  - mark external function args as `nocapture`
+  - implement support for some `#define` constants
+  - implement support for multiple CGo files in a single package
+- **standard library**
+  - `machine`: remove microbit matrix (moved to drivers repository)
+  - `machine`: refactor pins to use `Pin` type instead of `GPIO`
+  - `runtime`: print more interface types on panic, including `error`
+* **targets**
+  - `arm`: print an error on HardFault (including stack overflows)
+  - `atsamd21`: fix a bug in the ADC peripheral
+  - `atsamd21`: add support for I2S
+  - `feather-m0`: add support for this board
+  - `nrf51`: fix a bug in I2C
+  - `stm32f103xx`: fix a bug in I2C
+  - `syscall`: implement `Exit` on unix
+  - `trinket-m0`: add support for this board
+  - `wasm`: make _main_ example smaller
+  - `wasm`: don't cache wasm file in the server, for ease of debugging
+  - `wasm`: work around bug #41508 that caused a deadlock while linking
+  - `wasm`: add support for `js.FuncOf`
+
+0.5.0
+---
+- **compiler driver**
+  - use `wasm-ld` instead of `wasm-ld-8` on macOS
+  - drop dependency on `llvm-ar`
+  - fix linker script includes when running outside `TINYGOROOT`
+- **compiler**
+  - switch to LLVM 8
+  - add support for the Go 1.12 standard library (Go 1.11 is still supported)
+  - work around lack of escape analysis due to nil checks
+  - implement casting named structs and pointers to them
+  - fix int casting to use the source signedness
+  - fix some bugs around `make([]T, …)` with uncommon index types
+  - some other optimizations
+  - support interface asserts in interp for "math/rand" support
+  - resolve all func value targets at compile time (wasm-only at the moment)
+- **cgo**
+  - improve diagnostics
+  - implement C `struct`, `union`, and arrays
+  - fix CGo-related crash in libclang
+  - implement `C.struct_` types
+- **targets**
+  - all baremetal: pretend to be linux/arm instead of js/wasm
+  - `avr`: improve `uintptr` support
+  - `cortexm`: implement memmove intrinsic generated by LLVM
+  - `cortexm`: use the lld linker instead of `arm-none-eabi-ld`
+  - `darwin`: use custom syscall package that links to libSystem.dylib
+  - `microbit`: add blink example
+  - `samd21`: support I2C1
+  - `samd21`: machine/atsamd21: correct pad/pin handling when using both UART
+     and USBCDC interfaces at same time
+  - `stm32f4discovery`: add support for this board
+  - `wasm`: support async func values
+  - `wasm`: improve documentation and add extra example
+
+0.4.1
+---
+- **compiler**
+  - fix `objcopy` replacement to include the .data section in the firmware image
+  - use `llvm-ar-7` on Linux to fix the Docker image
+
+0.4.0
+---
+- **compiler**
+  - switch to the hardfloat ABI on ARM, which is more widely used
+  - avoid a dependency on `objcopy` (`arm-none-eabi-objcopy` etc.)
+  - fix a bug in `make([]T, n)` where `n` is 64-bits on a 32-bit platform
+  - adapt to a change in the AVR backend in LLVM 8
+  - directly support the .uf2 firmware format as used on Adafruit boards
+  - fix a bug when calling `panic()` at init time outside of the main package
+  - implement nil checks, which results in a ~5% increase in code size
+  - inline slice bounds checking, which results in a ~1% decrease in code size
+- **targets**
+  - `samd21`: fix a bug in port B pins
+  - `samd21`: implement SPI peripheral
+  - `samd21`: implement ADC peripheral
+  - `stm32`: fix a bug in timekeeping
+  - `wasm`: fix a bug in `wasm_exec.js` that caused corruption in linear memory
+     when running on Node.js.
+
+0.3.0
+---
+- **compiler**
+  - remove old `-initinterp` flag
+  - add support for macOS
+- **cgo**
+  - add support for bool/float/complex types
+- **standard library**
+  - `device/arm`: add support to disable/enable hardware interrupts
+  - `machine`: add CPU frequency for nrf-based boards
+  - `syscall`: add support for darwin/amd64
+- **targets**
+  - `circuitplay_express`: add support for this board
+  - `microbit`: add regular pin constants
+  - `samd21`: fix time function for goroutine support
+  - `samd21`: add support for USB-CDC (serial over USB)
+  - `samd21`: add support for pins in port B
+  - `samd21`: add support for pullup and pulldown pins
+  - `wasm`: add support for Safari in example
+
+
+0.2.0
+---
+- **command line**
+  - add version subcommand
+- **compiler**
+  - fix a bug in floating point comparisons with NaN values
+  - fix a bug when calling `panic` in package initialization code
+  - add support for comparing `complex64` and `complex128`
+- **cgo**
+  - add support for external globals
+  - add support for pointers and function pointers
+- **standard library**
+  - `fmt`: initial support, `fmt.Println` works
+  - `math`: support for most/all functions
+  - `os`: initial support (only stdin/stdout/stderr)
+  - `reflect`: initial support
+  - `syscall`: add support for amd64, arm, and arm64

CODE-OF-CONDUCT.md

@@ -0,0 +1,76 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to make participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, sex characteristics, gender identity and expression,
+level of experience, education, socio-economic status, nationality, personal
+appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies within all project spaces, and it also applies when
+an individual is representing the project or its community in public spaces.
+Examples of representing a project or community include using an official
+project e-mail address, posting via an official social media account, or acting
+as an appointed representative at an online or offline event. Representation of
+a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at [conduct@tinygo.org](mailto:conduct@tinygo.org). All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see
+https://www.contributor-covenant.org/faq

CONTRIBUTING.md

@@ -0,0 +1,52 @@
+# How to contribute
+
+Thank you for your interest in improving TinyGo.
+
+We would like your help to make this project better, so we appreciate any contributions. See if one of the following descriptions matches your situation:
+
+### New to TinyGo
+
+We'd love to get your feedback on getting started with TinyGo. Run into any difficulty, confusion, or anything else? You are not alone. We want to know about your experience, so we can help the next people. Please open a Github issue with your questions, or you can also get in touch directly with us on our Slack channel at [https://gophers.slack.com/messages/CDJD3SUP6](https://gophers.slack.com/messages/CDJD3SUP6).
+
+### Something in TinyGo is not working as you expect
+
+Please open a Github issue with your problem, and we will be happy to assist.
+
+### Something in Go that you want/need does not appear to be in TinyGo
+
+We probably have not implemented it yet. Please take a look at our [Roadmap](https://github.com/tinygo-org/tinygo/wiki/Roadmap). Your pull request adding the functionality to TinyGo would be greatly appreciated.
+
+Please open a Github issue. We want to help, and also make sure that there is no duplications of efforts. Sometimes what you need is already being worked on by someone else.
+
+A long tail of small (and large) language features haven't been implemented yet. In almost all cases, the compiler will show a `todo:` error from `compiler/compiler.go` when you try to use it. You can try implementing it, or open a bug report with a small code sample that fails to compile.
+
+### Some specific hardware you want to use does not appear to be in TinyGo
+
+As above, we probably have not implemented it yet. Your contribution adding the hardware support to TinyGo would be greatly appreciated.
+
+Please start by opening a Github issue. We want to help you to help us to help you.
+
+Lots of targets/boards are still unsupported. Adding an architecture often requires a few compiler changes, but if the architecture is supported you can try implementing support for a new chip or board in `src/runtime`. For details, see [this wiki entry on adding archs/chips/boards](https://github.com/tinygo-org/tinygo/wiki/Adding-a-new-board).
+
+Microcontrollers have lots of peripherals (I2C, SPI, ADC, etc.) and many don't have an implementation yet in the `machine` package. Adding support for new peripherals is very useful.
+
+## How to use our Github repository
+
+The `release` branch of this repo will always have the latest released version of TinyGo. All of the active development work for the next release will take place in the `dev` branch. TinyGo will use semantic versioning and will create a tag/release for each release.
+
+Here is how to contribute back some code or documentation:
+
+- Fork repo
+- Create a feature branch off of the `dev` branch
+- Make some useful change
+- Make sure the tests still pass
+- Submit a pull request against the `dev` branch.
+- Be kind
+
+## How to run tests
+
+To run the tests:
+
+```
+make test
+```

CONTRIBUTORS

@@ -0,0 +1,18 @@
+# This is the official list of TinyGo authors for copyright purposes.
+#
+# This file is not actively maintained.
+# To be included, send a change adding the individual or
+# company who owns a contribution's copyright.
+#
+# Names should be added to this file as one of
+#     Organization's name
+#     Individual's name <submission email address>
+#     Individual's name <submission email address> <email2> <emailN>
+#
+# Please keep the list sorted.
+
+Ayke van Laethem <aykevanlaethem@gmail.com>
+Daniel Esteban <conejo@conejo.me>
+Loon, LLC.
+Ron Evans <ron@hybridgroup.com>
+Nia Weiss <niaow1234@gmail.com>

Dockerfile

@@ -1,46 +1,51 @@
-# TinyGo base stage just installs LLVM 7 and the TinyGo compiler itself.
-FROM golang:latest AS tinygo-base
+# TinyGo base stage installs the most recent Go 1.15.x, LLVM 11 and the TinyGo compiler itself.
+FROM golang:1.15 AS tinygo-base
 
 RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
-    echo "deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-7 main" >> /etc/apt/sources.list && \
+    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-11 main" >> /etc/apt/sources.list && \
     apt-get update && \
-    apt-get install -y llvm-7-dev libclang-7-dev
+    apt-get install -y llvm-11-dev libclang-11-dev lld-11 git
 
-RUN wget -O- https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+COPY . /tinygo
 
-COPY . /go/src/github.com/aykevl/tinygo
+# remove submodules directories and re-init them to fix any hard-coded paths
+# after copying the tinygo directory in the previous step.
+RUN cd /tinygo/ && \
+    rm -rf ./lib/* && \
+    git submodule sync && \
+    git submodule update --init --recursive --force
 
-RUN cd /go/src/github.com/aykevl/tinygo/ && \
-    dep ensure --vendor-only && \
-    go install /go/src/github.com/aykevl/tinygo/
+COPY ./lib/picolibc-include/* /tinygo/lib/picolibc-include/
+
+RUN cd /tinygo/ && \
+    go install /tinygo/
 
 # tinygo-wasm stage installs the needed dependencies to compile TinyGo programs for WASM.
 FROM tinygo-base AS tinygo-wasm
 
 COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/src /go/src/github.com/aykevl/tinygo/src
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/targets /go/src/github.com/aykevl/tinygo/targets
+COPY --from=tinygo-base /tinygo/src /tinygo/src
+COPY --from=tinygo-base /tinygo/targets /tinygo/targets
 
-RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
-    echo "deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-7 main" >> /etc/apt/sources.list && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y libllvm7 lld-7
+    apt-get install -y make clang-11 libllvm11 lld-11 && \
+    make wasi-libc
 
 # tinygo-avr stage installs the needed dependencies to compile TinyGo programs for AVR microcontrollers.
 FROM tinygo-base AS tinygo-avr
 
 COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/src /go/src/github.com/aykevl/tinygo/src
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/targets /go/src/github.com/aykevl/tinygo/targets
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/Makefile /go/src/github.com/aykevl/tinygo/
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/tools /go/src/github.com/aykevl/tinygo/tools
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/lib /go/src/github.com/aykevl/tinygo/lib
+COPY --from=tinygo-base /tinygo/src /tinygo/src
+COPY --from=tinygo-base /tinygo/targets /tinygo/targets
+COPY --from=tinygo-base /tinygo/Makefile /tinygo/
+COPY --from=tinygo-base /tinygo/tools /tinygo/tools
+COPY --from=tinygo-base /tinygo/lib /tinygo/lib
 
-RUN cd /go/src/github.com/aykevl/tinygo/ && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y apt-utils python3 make binutils-avr gcc-avr avr-libc && \
+    apt-get install -y apt-utils make binutils-avr gcc-avr avr-libc && \
     make gen-device-avr && \
-    apt-get remove -y python3 make && \
     apt-get autoremove -y && \
     apt-get clean
 
@@ -48,33 +53,27 @@ RUN cd /go/src/github.com/aykevl/tinygo/ && \
 FROM tinygo-base AS tinygo-arm
 
 COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/src /go/src/github.com/aykevl/tinygo/src
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/targets /go/src/github.com/aykevl/tinygo/targets
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/Makefile /go/src/github.com/aykevl/tinygo/
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/tools /go/src/github.com/aykevl/tinygo/tools
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/lib /go/src/github.com/aykevl/tinygo/lib
+COPY --from=tinygo-base /tinygo/src /tinygo/src
+COPY --from=tinygo-base /tinygo/targets /tinygo/targets
+COPY --from=tinygo-base /tinygo/Makefile /tinygo/
+COPY --from=tinygo-base /tinygo/tools /tinygo/tools
+COPY --from=tinygo-base /tinygo/lib /tinygo/lib
 
-RUN cd /go/src/github.com/aykevl/tinygo/ && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y apt-utils python3 make binutils-arm-none-eabi clang-7 && \
-    make gen-device-nrf && make gen-device-stm32 && \
-    apt-get remove -y python3 make && \
-    apt-get autoremove -y && \
-    apt-get clean
+    apt-get install -y apt-utils make clang-11 && \
+    make gen-device-nrf && make gen-device-stm32
 
 # tinygo-all stage installs the needed dependencies to compile TinyGo programs for all platforms.
 FROM tinygo-wasm AS tinygo-all
 
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/Makefile /go/src/github.com/aykevl/tinygo/
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/tools /go/src/github.com/aykevl/tinygo/tools
-COPY --from=tinygo-base /go/src/github.com/aykevl/tinygo/lib /go/src/github.com/aykevl/tinygo/lib
+COPY --from=tinygo-base /tinygo/Makefile /tinygo/
+COPY --from=tinygo-base /tinygo/tools /tinygo/tools
+COPY --from=tinygo-base /tinygo/lib /tinygo/lib
 
-RUN cd /go/src/github.com/aykevl/tinygo/ && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y apt-utils python3 make binutils-arm-none-eabi clang-7 binutils-avr gcc-avr avr-libc && \
-    make gen-device && \
-    apt-get remove -y python3 make && \
-    apt-get autoremove -y && \
-    apt-get clean
+    apt-get install -y apt-utils make clang-11 binutils-avr gcc-avr avr-libc && \
+    make gen-device
 
 CMD ["tinygo"]

Gopkg.lock

@@ -1,44 +0,0 @@
-# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
-
-
-[[projects]]
-  branch = "master"
-  digest = "1:f250e2a6d7e4f9ebc5ba37e5e2ec91b46eb1399ee43f2fdaeb20cd4fd1aeee59"
-  name = "github.com/aykevl/go-llvm"
-  packages = ["."]
-  pruneopts = "UT"
-  revision = "d8539684f173a591ea9474d6262ac47ef2277d64"
-
-[[projects]]
-  branch = "master"
-  digest = "1:d1102ae84d8c9318db4ce2ad2673eb2bf54569ab2a4a5d57e70d8aef726b681d"
-  name = "golang.org/x/tools"
-  packages = [
-    "go/ast/astutil",
-    "go/buildutil",
-    "go/gcexportdata",
-    "go/internal/cgo",
-    "go/internal/gcimporter",
-    "go/loader",
-    "go/packages",
-    "go/ssa",
-    "go/ssa/ssautil",
-    "go/types/typeutil",
-    "internal/fastwalk",
-    "internal/gopathwalk",
-    "internal/semver",
-  ]
-  pruneopts = "UT"
-  revision = "3e7aa9e59977626dc60433e9aeadf1bb63d28295"
-
-[solve-meta]
-  analyzer-name = "dep"
-  analyzer-version = 1
-  input-imports = [
-    "github.com/aykevl/go-llvm",
-    "golang.org/x/tools/go/loader",
-    "golang.org/x/tools/go/ssa",
-    "golang.org/x/tools/go/ssa/ssautil",
-  ]
-  solver-name = "gps-cdcl"
-  solver-version = 1

Gopkg.toml

@@ -1,11 +0,0 @@
-[[constraint]]
-  branch = "master"
-  name = "github.com/aykevl/go-llvm"
-
-[[constraint]]
-  branch = "master"
-  name = "golang.org/x/tools"
-
-[prune]
-  go-tests = true
-  unused-packages = true

LICENSE

@@ -1,4 +1,10 @@
-Copyright (c) 2018 Ayke van Laethem. All rights reserved.
+Copyright (c) 2018-2021 TinyGo Authors. All rights reserved.
+
+TinyGo includes portions of the Go standard library.
+Copyright (c) 2009-2021 The Go Authors. All rights reserved.
+
+TinyGo includes portions of LLVM, which is under the Apache License v2.0 with
+LLVM Exceptions. See https://llvm.org/LICENSE.txt for license information.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are

Makefile

@@ -1,113 +1,456 @@
 
 # aliases
-all: tgo
-tgo: build/tgo
+all: tinygo
 
-.PHONY: all tgo run-test run-blinky run-blinky2 clean fmt gen-device gen-device-nrf gen-device-avr
+# Default build and source directories, as created by `make llvm-build`.
+LLVM_BUILDDIR ?= llvm-build
+LLVM_PROJECTDIR ?= llvm-project
+CLANG_SRC ?= $(LLVM_PROJECTDIR)/clang
+LLD_SRC ?= $(LLVM_PROJECTDIR)/lld
 
-TARGET ?= unix
+# Try to autodetect LLVM build tools.
+detect = $(shell command -v $(1) 2> /dev/null && echo $(1))
+CLANG ?= $(word 1,$(abspath $(call detect,llvm-build/bin/clang))$(call detect,clang-11)$(call detect,clang-10)$(call detect,clang))
+LLVM_AR ?= $(word 1,$(abspath $(call detect,llvm-build/bin/llvm-ar))$(call detect,llvm-ar-11)$(call detect,llvm-ar-10)$(call detect,llvm-ar))
+LLVM_NM ?= $(word 1,$(abspath $(call detect,llvm-build/bin/llvm-nm))$(call detect,llvm-nm-11)$(call detect,llvm-nm-10)$(call detect,llvm-nm))
 
-ifeq ($(TARGET),unix)
-# Regular *nix system.
+# Go binary and GOROOT to select
+GO ?= go
+export GOROOT = $(shell $(GO) env GOROOT)
 
-else ifeq ($(TARGET),pca10040)
-# PCA10040: nRF52832 development board
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
+# md5sum binary
+MD5SUM = md5sum
 
-else ifeq ($(TARGET),microbit)
-# BBC micro:bit
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
+# tinygo binary for tests
+TINYGO ?= $(word 1,$(call detect,tinygo)$(call detect,build/tinygo))
 
-else ifeq ($(TARGET),reelboard)
-# reel board
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
-
-else ifeq ($(TARGET),bluepill)
-# "blue pill" development board
-# See: https://wiki.stm32duino.com/index.php?title=Blue_Pill
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
-
-else ifeq ($(TARGET),arduino)
-OBJCOPY = avr-objcopy
-TGOFLAGS += -target $(TARGET)
+# Use CCACHE for LLVM if possible
+ifneq (, $(shell command -v ccache 2> /dev/null))
+    LLVM_OPTION += '-DLLVM_CCACHE_BUILD=ON'
+endif
 
+# Allow enabling LLVM assertions
+ifeq (1, $(ASSERT))
+    LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=ON'
 else
-$(error Unknown target)
-
+    LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=OFF'
 endif
 
+.PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-nxp gen-device-avr
 
+LLVM_COMPONENTS = all-targets analysis asmparser asmprinter bitreader bitwriter codegen core coroutines coverage debuginfodwarf executionengine frontendopenmp instrumentation interpreter ipo irreader linker lto mc mcjit objcarcopts option profiledata scalaropts support target
 
-run-test: build/test
-	./build/test
+ifeq ($(OS),Windows_NT)
+    EXE = .exe
+    START_GROUP = -Wl,--start-group
+    END_GROUP = -Wl,--end-group
 
-run-blinky: run-blinky2
-run-blinky2: build/blinky2
-	./build/blinky2
+    # LLVM compiled using MinGW on Windows appears to have problems with threads.
+    # Without this flag, linking results in errors like these:
+    #     libLLVMSupport.a(Threading.cpp.obj):Threading.cpp:(.text+0x55): undefined reference to `std::thread::hardware_concurrency()'
+    LLVM_OPTION += -DLLVM_ENABLE_THREADS=OFF -DLLVM_ENABLE_PIC=OFF
 
-ifeq ($(TARGET),pca10040)
-flash-%: build/%.hex
-	nrfjprog -f nrf52 --sectorerase --program $< --reset
-else ifeq ($(TARGET),microbit)
-flash-%: build/%.hex
-	openocd -f interface/cmsis-dap.cfg -f target/nrf51.cfg -c 'program $< reset exit'
-else ifeq ($(TARGET),reelboard)
-flash-%: build/%.hex
-	openocd -f interface/cmsis-dap.cfg -f target/nrf51.cfg -c 'program $< reset exit'
-else ifeq ($(TARGET),arduino)
-flash-%: build/%.hex
-	avrdude -c arduino -p atmega328p -P /dev/ttyACM0 -U flash:w:$<
-else ifeq ($(TARGET),bluepill)
-flash-%: build/%.hex
-	openocd -f interface/stlink-v2.cfg -f target/stm32f1x.cfg -c 'program $< reset exit'
+    CGO_CPPFLAGS += -DCINDEX_NO_EXPORTS
+    CGO_LDFLAGS += -static -static-libgcc -static-libstdc++
+    CGO_LDFLAGS_EXTRA += -lversion
+
+    LIBCLANG_NAME = libclang
+
+else ifeq ($(shell uname -s),Darwin)
+    MD5SUM = md5
+    LIBCLANG_NAME = clang
+else ifeq ($(shell uname -s),FreeBSD)
+    MD5SUM = md5
+    LIBCLANG_NAME = clang
+    START_GROUP = -Wl,--start-group
+    END_GROUP = -Wl,--end-group
+else
+    LIBCLANG_NAME = clang
+    START_GROUP = -Wl,--start-group
+    END_GROUP = -Wl,--end-group
 endif
 
+# Libraries that should be linked in for the statically linked Clang.
+CLANG_LIB_NAMES = clangAnalysis clangARCMigrate clangAST clangASTMatchers clangBasic clangCodeGen clangCrossTU clangDriver clangDynamicASTMatchers clangEdit clangFormat clangFrontend clangFrontendTool clangHandleCXX clangHandleLLVM clangIndex clangLex clangParse clangRewrite clangRewriteFrontend clangSema clangSerialization clangStaticAnalyzerCheckers clangStaticAnalyzerCore clangStaticAnalyzerFrontend clangTooling clangToolingASTDiff clangToolingCore clangToolingInclusions
+CLANG_LIBS = $(START_GROUP) $(addprefix -l,$(CLANG_LIB_NAMES)) $(END_GROUP) -lstdc++
+
+# Libraries that should be linked in for the statically linked LLD.
+LLD_LIB_NAMES = lldCOFF lldCommon lldCore lldDriver lldELF lldMachO lldMinGW lldReaderWriter lldWasm lldYAML
+LLD_LIBS = $(START_GROUP) $(addprefix -l,$(LLD_LIB_NAMES)) $(END_GROUP)
+
+# Other libraries that are needed to link TinyGo.
+EXTRA_LIB_NAMES = LLVMInterpreter
+
+# These build targets appear to be the only ones necessary to build all TinyGo
+# dependencies. Only building a subset significantly speeds up rebuilding LLVM.
+# The Makefile rules convert a name like lldELF to lib/liblldELF.a to match the
+# library path (for ninja).
+# This list also includes a few tools that are necessary as part of the full
+# TinyGo build.
+NINJA_BUILD_TARGETS = clang llvm-config llvm-ar llvm-nm $(addprefix lib/lib,$(addsuffix .a,$(LIBCLANG_NAME) $(CLANG_LIB_NAMES) $(LLD_LIB_NAMES) $(EXTRA_LIB_NAMES)))
+
+# For static linking.
+ifneq ("$(wildcard $(LLVM_BUILDDIR)/bin/llvm-config*)","")
+    CGO_CPPFLAGS+=$(shell $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(LLVM_BUILDDIR))/tools/clang/include -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
+    CGO_CXXFLAGS=-std=c++14
+    CGO_LDFLAGS+=$(abspath $(LLVM_BUILDDIR))/lib/lib$(LIBCLANG_NAME).a -L$(abspath $(LLVM_BUILDDIR)/lib) $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
+endif
+
+
 clean:
 	@rm -rf build
 
+FMT_PATHS = ./*.go builder cgo compiler interp loader src/device/arm src/examples src/machine src/os src/reflect src/runtime src/sync src/syscall src/internal/reflectlite transform
 fmt:
-	@go fmt . ./compiler ./interp ./loader ./ir ./src/device/arm ./src/examples/* ./src/machine ./src/runtime ./src/sync
-	@go fmt ./testdata/*.go
+	@gofmt -l -w $(FMT_PATHS)
+fmt-check:
+	@unformatted=$$(gofmt -l $(FMT_PATHS)); [ -z "$$unformatted" ] && exit 0; echo "Unformatted:"; for fn in $$unformatted; do echo "  $$fn"; done; exit 1
 
-test:
-	@go test -v .
 
-gen-device: gen-device-avr gen-device-nrf gen-device-sam gen-device-stm32
+gen-device: gen-device-avr gen-device-esp gen-device-nrf gen-device-sam gen-device-sifive gen-device-kendryte gen-device-nxp
+ifneq ($(STM32), 0)
+gen-device: gen-device-stm32
+endif
 
 gen-device-avr:
-	./tools/gen-device-avr.py lib/avr/packs/atmega src/device/avr/
-	./tools/gen-device-avr.py lib/avr/packs/tiny src/device/avr/
-	go fmt ./src/device/avr
+	@if [ ! -e lib/avr/README.md ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
+	$(GO) build -o ./build/gen-device-avr ./tools/gen-device-avr/
+	./build/gen-device-avr lib/avr/packs/atmega src/device/avr/
+	./build/gen-device-avr lib/avr/packs/tiny src/device/avr/
+	@GO111MODULE=off $(GO) fmt ./src/device/avr
 
-gen-device-nrf:
-	./tools/gen-device-svd.py lib/nrfx/mdk/ src/device/nrf/ --source=https://github.com/NordicSemiconductor/nrfx/tree/master/mdk
-	go fmt ./src/device/nrf
+build/gen-device-svd: ./tools/gen-device-svd/*.go
+	$(GO) build -o $@ ./tools/gen-device-svd/
 
-gen-device-sam:
-	./tools/gen-device-svd.py lib/cmsis-svd/data/Atmel/ src/device/sam/ --source=https://github.com/posborne/cmsis-svd/tree/master/data/Atmel
-	go fmt ./src/device/sam
+gen-device-esp: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Espressif-Community -interrupts=software lib/cmsis-svd/data/Espressif-Community/ src/device/esp/
+	GO111MODULE=off $(GO) fmt ./src/device/esp
+
+gen-device-nrf: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/NordicSemiconductor/nrfx/tree/master/mdk lib/nrfx/mdk/ src/device/nrf/
+	GO111MODULE=off $(GO) fmt ./src/device/nrf
+
+gen-device-nxp: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/NXP lib/cmsis-svd/data/NXP/ src/device/nxp/
+	GO111MODULE=off $(GO) fmt ./src/device/nxp
+
+gen-device-sam: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Atmel lib/cmsis-svd/data/Atmel/ src/device/sam/
+	GO111MODULE=off $(GO) fmt ./src/device/sam
+
+gen-device-sifive: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/SiFive-Community -interrupts=software lib/cmsis-svd/data/SiFive-Community/ src/device/sifive/
+	GO111MODULE=off $(GO) fmt ./src/device/sifive
+
+gen-device-kendryte: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Kendryte-Community -interrupts=software lib/cmsis-svd/data/Kendryte-Community/ src/device/kendryte/
+	GO111MODULE=off $(GO) fmt ./src/device/kendryte
+
+gen-device-stm32: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/tinygo-org/stm32-svd lib/stm32-svd/svd src/device/stm32/
+	GO111MODULE=off $(GO) fmt ./src/device/stm32
+
+
+# Get LLVM sources.
+$(LLVM_PROJECTDIR)/README.md:
+	git clone -b xtensa_release_11.0.0 --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
+llvm-source: $(LLVM_PROJECTDIR)/README.md
+
+# Configure LLVM.
+TINYGO_SOURCE_DIR=$(shell pwd)
+$(LLVM_BUILDDIR)/build.ninja: llvm-source
+	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/$(LLVM_PROJECTDIR)/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR;Xtensa" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_LIBEDIT=OFF -DLLVM_ENABLE_Z3_SOLVER=OFF -DLLVM_ENABLE_OCAMLDOC=OFF -DLLVM_ENABLE_LIBXML2=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
+
+# Build LLVM.
+$(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
+	cd $(LLVM_BUILDDIR); ninja $(NINJA_BUILD_TARGETS)
+
+
+# Build wasi-libc sysroot
+.PHONY: wasi-libc
+wasi-libc: lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a
+lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a:
+	@if [ ! -e lib/wasi-libc/Makefile ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
+	cd lib/wasi-libc && make -j4 WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)
 
-gen-device-stm32:
-	./tools/gen-device-svd.py lib/cmsis-svd/data/STMicro/ src/device/stm32/ --source=https://github.com/posborne/cmsis-svd/tree/master/data/STMicro
-	go fmt ./src/device/stm32
 
 # Build the Go compiler.
-build/tgo: *.go compiler/*.go interp/*.go loader/*.go ir/*.go
-	@mkdir -p build
-	go build -o build/tgo -i .
+tinygo:
+	@if [ ! -f "$(LLVM_BUILDDIR)/bin/llvm-config" ]; then echo "Fetch and build LLVM first by running:"; echo "  make llvm-source"; echo "  make $(LLVM_BUILDDIR)"; exit 1; fi
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags byollvm -ldflags="-X main.gitSha1=`git rev-parse --short HEAD`" .
 
-# Binary that can run on the host.
-build/%: src/examples/% src/examples/%/*.go build/tgo src/runtime/*.go
-	./build/tgo build $(TGOFLAGS) -size=short -o $@ $(subst src/,,$<)
+test: wasi-libc
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -buildmode exe -tags byollvm ./cgo ./compileopts ./compiler ./interp ./transform .
 
-# ELF file that can run on a microcontroller.
-build/%.elf: src/examples/% src/examples/%/*.go build/tgo src/runtime/*.go
-	./build/tgo build $(TGOFLAGS) -size=short -o $@ $(subst src/,,$<)
+# Test known-working standard library packages.
+# TODO: do this in one command, parallelize, and only show failing tests (no
+# implied -v flag).
+.PHONY: tinygo-test
+tinygo-test:
+	$(TINYGO) test container/heap
+	$(TINYGO) test container/list
+	$(TINYGO) test container/ring
+	$(TINYGO) test crypto/des
+	$(TINYGO) test encoding/ascii85
+	$(TINYGO) test encoding/base32
+	$(TINYGO) test encoding/hex
+	$(TINYGO) test hash/adler32
+	$(TINYGO) test hash/fnv
+	$(TINYGO) test hash/crc64
+	$(TINYGO) test math
+	$(TINYGO) test math/cmplx
+	$(TINYGO) test text/scanner
+	$(TINYGO) test unicode/utf8
 
-# Convert executable to Intel hex file (for flashing).
-build/%.hex: build/%.elf
-	$(OBJCOPY) -O ihex $^ $@
+.PHONY: smoketest
+smoketest:
+	$(TINYGO) version
+	# test all examples (except pwm)
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/adc
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinkm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/button
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/button2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/echo
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/mcp3008
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit            examples/microbit-blink
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit-v2         examples/microbit-blink
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pininterrupt
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/serial
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/systick
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/test
+	@$(MD5SUM) test.hex
+	# test simulated boards on play.tinygo.org
+	$(TINYGO) build             -o test.wasm -tags=arduino              examples/blinky1
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=hifive1b             examples/blinky1
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=reelboard            examples/blinky1
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=pca10040             examples/blinky2
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=pca10056             examples/blinky2
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=circuitplay_express  examples/blinky1
+	@$(MD5SUM) test.wasm
+	# test all targets/boards
+	$(TINYGO) build -size short -o test.hex -target=pca10040-s132v6     examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit            examples/echo
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit-s110v8     examples/echo
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nrf52840-mdk        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10031            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=reelboard           examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=reelboard           examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10056            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10056            examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10059            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10059            examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m0          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=trinket-m0          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-bluefruit examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=clue-alpha          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.gba -target=gameboy-advance     examples/gba-display
+	@$(MD5SUM) test.gba
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pybadge             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=metro-m4-airlift    examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=particle-argon      examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=particle-boron      examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=particle-xenon      examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pinetime-devkit0    examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=x9pro               examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10056-s140v7     examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=reelboard-s140v7    examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=wioterminal         examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pygamer             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=xiao                examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/dac
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/dac
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-nrf52840  	examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-nrf52840  examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=qtpy  				examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=teensy40            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=teensy36            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=p1am-100            examples/blinky1
+	@$(MD5SUM) test.hex
+	# test pwm
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/pwm
+	@$(MD5SUM) test.hex
+ifneq ($(STM32), 0)
+	$(TINYGO) build -size short -o test.hex -target=bluepill            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-stm32f405   examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=lgt92               examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nucleo-f103rb       examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nucleo-f722ze       examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nucleo-l432kc       examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nucleo-l552ze       examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco        examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco-1      examples/blinky1
+	@$(MD5SUM) test.hex
+endif
+ifneq ($(AVR), 0)
+	$(TINYGO) build -size short -o test.hex -target=atmega1284p         examples/serial
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino             examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino -scheduler=tasks  examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino-nano        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=digispark           examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=digispark -gc=leaking examples/blinky1
+	@$(MD5SUM) test.hex
+endif
+ifneq ($(XTENSA), 0)
+	$(TINYGO) build -size short -o test.bin -target=esp32-mini32      	examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=nodemcu             examples/blinky1
+	@$(MD5SUM) test.bin
+endif
+	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=hifive1-qemu        examples/serial
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=maixbit             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/export
+	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/main
+	# test various compiler flags
+	$(TINYGO) build -size short -o test.hex -target=pca10040 -gc=none -scheduler=none examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040 -opt=1     examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build             -o test.nro -target=nintendoswitch      examples/serial
+	@$(MD5SUM) test.nro
+	$(TINYGO) build -size short -o test.hex -target=pca10040 -opt=0     ./testdata/stdlib.go
+	@$(MD5SUM) test.hex
+
+
+wasmtest:
+	$(GO) test ./tests/wasm
+
+build/release: tinygo gen-device wasi-libc
+	@mkdir -p build/release/tinygo/bin
+	@mkdir -p build/release/tinygo/lib/clang/include
+	@mkdir -p build/release/tinygo/lib/CMSIS/CMSIS
+	@mkdir -p build/release/tinygo/lib/compiler-rt/lib
+	@mkdir -p build/release/tinygo/lib/nrfx
+	@mkdir -p build/release/tinygo/lib/picolibc/newlib/libc
+	@mkdir -p build/release/tinygo/lib/wasi-libc
+	@mkdir -p build/release/tinygo/pkg/armv6m-none-eabi
+	@mkdir -p build/release/tinygo/pkg/armv7m-none-eabi
+	@mkdir -p build/release/tinygo/pkg/armv7em-none-eabi
+	@echo copying source files
+	@cp -p  build/tinygo$(EXE)           build/release/tinygo/bin
+	@cp -p $(abspath $(CLANG_SRC))/lib/Headers/*.h build/release/tinygo/lib/clang/include
+	@cp -rp lib/CMSIS/CMSIS/Include      build/release/tinygo/lib/CMSIS/CMSIS
+	@cp -rp lib/CMSIS/README.md          build/release/tinygo/lib/CMSIS
+	@cp -rp lib/compiler-rt/lib/builtins build/release/tinygo/lib/compiler-rt/lib
+	@cp -rp lib/compiler-rt/LICENSE.TXT  build/release/tinygo/lib/compiler-rt
+	@cp -rp lib/compiler-rt/README.txt   build/release/tinygo/lib/compiler-rt
+	@cp -rp lib/nrfx/*                   build/release/tinygo/lib/nrfx
+	@cp -rp lib/picolibc/newlib/libc/ctype       build/release/tinygo/lib/picolibc/newlib/libc
+	@cp -rp lib/picolibc/newlib/libc/include     build/release/tinygo/lib/picolibc/newlib/libc
+	@cp -rp lib/picolibc/newlib/libc/locale      build/release/tinygo/lib/picolibc/newlib/libc
+	@cp -rp lib/picolibc/newlib/libc/string      build/release/tinygo/lib/picolibc/newlib/libc
+	@cp -rp lib/picolibc/newlib/libc/tinystdio   build/release/tinygo/lib/picolibc/newlib/libc
+	@cp -rp lib/picolibc-include         build/release/tinygo/lib
+	@cp -rp lib/wasi-libc/sysroot        build/release/tinygo/lib/wasi-libc/sysroot
+	@cp -rp src                          build/release/tinygo/src
+	@cp -rp targets                      build/release/tinygo/targets
+	./build/tinygo build-library -target=armv6m-none-eabi  -o build/release/tinygo/pkg/armv6m-none-eabi/compiler-rt.a compiler-rt
+	./build/tinygo build-library -target=armv7m-none-eabi  -o build/release/tinygo/pkg/armv7m-none-eabi/compiler-rt.a compiler-rt
+	./build/tinygo build-library -target=armv7em-none-eabi -o build/release/tinygo/pkg/armv7em-none-eabi/compiler-rt.a compiler-rt
+	./build/tinygo build-library -target=armv6m-none-eabi  -o build/release/tinygo/pkg/armv6m-none-eabi/picolibc.a picolibc
+	./build/tinygo build-library -target=armv7m-none-eabi  -o build/release/tinygo/pkg/armv7m-none-eabi/picolibc.a picolibc
+	./build/tinygo build-library -target=armv7em-none-eabi -o build/release/tinygo/pkg/armv7em-none-eabi/picolibc.a picolibc
+
+release: build/release
+	tar -czf build/release.tar.gz -C build/release tinygo
+
+deb: build/release
+	@mkdir -p build/release-deb/usr/local/bin
+	@mkdir -p build/release-deb/usr/local/lib
+	cp -ar build/release/tinygo build/release-deb/usr/local/lib/tinygo
+	ln -sf ../lib/tinygo/bin/tinygo build/release-deb/usr/local/bin/tinygo
+	fpm -f -s dir -t deb -n tinygo -v $(shell grep "const Version = " goenv/version.go | awk '{print $$NF}') -m '@tinygo-org' --description='TinyGo is a Go compiler for small places.' --license='BSD 3-Clause' --url=https://tinygo.org/ --deb-changelog CHANGELOG.md -p build/release.deb -C ./build/release-deb

README.md

@@ -1,144 +1,115 @@
-# TinyGo - Go compiler for microcontrollers
+# TinyGo - Go compiler for small places
 
-[![Build Status](https://travis-ci.com/aykevl/tinygo.svg?branch=master)](https://travis-ci.com/aykevl/tinygo)
+[![CircleCI](https://circleci.com/gh/tinygo-org/tinygo/tree/dev.svg?style=svg)](https://circleci.com/gh/tinygo-org/tinygo/tree/dev) [![Build Status](https://dev.azure.com/tinygo/tinygo/_apis/build/status/tinygo-CI?branchName=dev)](https://dev.azure.com/tinygo/tinygo/_build/latest?definitionId=1&branchName=dev)
 
-> We never expected Go to be an embedded language and so it's got serious
-> problems [...].
+TinyGo is a Go compiler intended for use in small places such as microcontrollers, WebAssembly (Wasm), and command-line tools.
 
--- Rob Pike, [GopherCon 2014 Opening Keynote](https://www.youtube.com/watch?v=VoS7DsT1rdM&feature=youtu.be&t=2799)
+It reuses libraries used by the [Go language tools](https://golang.org/pkg/go/) alongside [LLVM](http://llvm.org) to provide an alternative way to compile programs written in the Go programming language.
 
-TinyGo is a project to bring Go to microcontrollers and small systems with a
-single processor core. It is similar to [emgo](https://github.com/ziutek/emgo)
-but a major difference is that I want to keep the Go memory model (which implies
-garbage collection of some sort). Another difference is that TinyGo uses LLVM
-internally instead of emitting C, which hopefully leads to smaller and more
-efficient code and certainly leads to more flexibility.
-
-My original reasoning was: if [Python](https://micropython.org/) can run on
-microcontrollers, then certainly [Go](https://golang.org/) should be able to and
-run on even lower level micros.
-
-Example program (blinky):
+Here is an example program that blinks the built-in LED when run directly on any supported board with onboard LED:
 
 ```go
+package main
+
 import (
-	"machine"
-	"time"
+    "machine"
+    "time"
 )
 
 func main() {
-	led := machine.GPIO{machine.LED}
-	led.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
-	for {
-		led.Low()
-		time.Sleep(time.Millisecond * 1000)
+    led := machine.LED
+    led.Configure(machine.PinConfig{Mode: machine.PinOutput})
+    for {
+        led.Low()
+        time.Sleep(time.Millisecond * 1000)
 
-		led.High()
-		time.Sleep(time.Millisecond * 1000)
-	}
+        led.High()
+        time.Sleep(time.Millisecond * 1000)
+    }
 }
 ```
 
-Currently supported features:
+The above program can be compiled and run without modification on an Arduino Uno, an Adafruit ItsyBitsy M0, or any of the supported boards that have a built-in LED, just by setting the correct TinyGo compiler target. For example, this compiles and flashes an Arduino Uno:
 
-  * control flow
-  * many (but not all) basic types: most ints, floats, strings, structs
-  * function calling
-  * interfaces for basic types (with type switches and asserts)
-  * goroutines (very initial support)
-  * function pointers (non-blocking)
-  * interface methods
-  * standard library (but most packages won't work due to missing language
-    features)
-  * slices (partially)
-  * maps (very rough, unfinished)
-  * defer
-  * closures
-  * bound methods
-  * complex numbers (except for arithmetic)
-
-Not yet supported:
-
-  * complex arithmetic
-  * garbage collection
-  * recover
-  * channels
-  * introspection (if it ever gets implemented)
-  * ...
+```shell
+tinygo flash -target arduino examples/blinky1
+```
 
 ## Installation
 
-See the [getting started instructions](https://tinygo.org/getting-started/).
+See the [getting started instructions](https://tinygo.org/getting-started/) for information on how to install TinyGo, as well as how to run the TinyGo compiler using our Docker container.
 
-### Running with Docker
+## Supported boards/targets
 
-A docker container exists for easy access to the `tinygo` CLI:
+You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.
 
-```sh
-$ docker run --rm -v $(pwd):/src tinygo/tinygo tinygo build -o /src/wasm.wasm -target wasm examples/wasm
-```
+The following 55 microcontroller boards are currently supported:
 
-Note that you cannot run `tinygo flash` from inside the docker container,
-so it is less useful for microcontroller development.
+* [Adafruit Circuit Playground Bluefruit](https://www.adafruit.com/product/4333)
+* [Adafruit Circuit Playground Express](https://www.adafruit.com/product/3333)
+* [Adafruit CLUE](https://www.adafruit.com/product/4500)
+* [Adafruit Feather M0](https://www.adafruit.com/product/2772)
+* [Adafruit Feather M4](https://www.adafruit.com/product/3857)
+* [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062)
+* [Adafruit Feather STM32F405 Express](https://www.adafruit.com/product/4382)
+* [Adafruit ItsyBitsy M0](https://www.adafruit.com/product/3727)
+* [Adafruit ItsyBitsy M4](https://www.adafruit.com/product/3800)
+* [Adafruit ItsyBitsy nRF52840](https://www.adafruit.com/product/4481)
+* [Adafruit Matrix Portal M4](https://www.adafruit.com/product/4745)
+* [Adafruit Metro M4 Express Airlift](https://www.adafruit.com/product/4000)
+* [Adafruit PyBadge](https://www.adafruit.com/product/4200)
+* [Adafruit PyGamer](https://www.adafruit.com/product/4242)
+* [Adafruit PyPortal](https://www.adafruit.com/product/4116)
+* [Adafruit QT Py](https://www.adafruit.com/product/4600)
+* [Adafruit Trinket M0](https://www.adafruit.com/product/3500)
+* [Arduino Mega 2560](https://store.arduino.cc/arduino-mega-2560-rev3)
+* [Arduino MKR1000](https://store.arduino.cc/arduino-mkr1000-wifi)
+* [Arduino Nano](https://store.arduino.cc/arduino-nano)
+* [Arduino Nano33 IoT](https://store.arduino.cc/nano-33-iot)
+* [Arduino Uno](https://store.arduino.cc/arduino-uno-rev3)
+* [Arduino Zero](https://store.arduino.cc/usa/arduino-zero)
+* [BBC micro:bit](https://microbit.org/)
+* [BBC micro:bit v2](https://microbit.org/new-microbit/)
+* [Digispark](http://digistump.com/products/1)
+* [Dragino LoRaWAN GPS Tracker LGT-92](http://www.dragino.com/products/lora-lorawan-end-node/item/142-lgt-92.html)
+* [ESP32](https://www.espressif.com/en/products/socs/esp32)
+* [ESP8266](https://www.espressif.com/en/products/socs/esp8266)
+* [Game Boy Advance](https://en.wikipedia.org/wiki/Game_Boy_Advance)
+* [Makerdiary nRF52840-MDK](https://wiki.makerdiary.com/nrf52840-mdk/)
+* [Makerdiary nRF52840-MDK USB Dongle](https://wiki.makerdiary.com/nrf52840-mdk-usb-dongle/)
+* [nice!nano](https://docs.nicekeyboards.com/#/nice!nano/)
+* [Nintendo Switch](https://www.nintendo.com/switch/)
+* [Nordic Semiconductor PCA10031](https://www.nordicsemi.com/eng/Products/nRF51-Dongle)
+* [Nordic Semiconductor PCA10040](https://www.nordicsemi.com/eng/Products/Bluetooth-low-energy/nRF52-DK)
+* [Nordic Semiconductor PCA10056](https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-DK)
+* [Particle Argon](https://docs.particle.io/datasheets/wi-fi/argon-datasheet/)
+* [Particle Boron](https://docs.particle.io/datasheets/cellular/boron-datasheet/)
+* [Particle Xenon](https://docs.particle.io/datasheets/discontinued/xenon-datasheet/)
+* [Phytec reel board](https://www.phytec.eu/product-eu/internet-of-things/reelboard/)
+* [PineTime DevKit](https://www.pine64.org/pinetime/)
+* [PJRC Teensy 3.6](https://www.pjrc.com/store/teensy36.html)
+* [PJRC Teensy 4.0](https://www.pjrc.com/store/teensy40.html)
+* [ProductivityOpen P1AM-100](https://facts-engineering.github.io/modules/P1AM-100/P1AM-100.html)
+* [Seeed Wio Terminal](https://www.seeedstudio.com/Wio-Terminal-p-4509.html)
+* [Seeed Seeeduino XIAO](https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html)
+* [Seeed Sipeed MAix BiT](https://www.seeedstudio.com/Sipeed-MAix-BiT-for-RISC-V-AI-IoT-p-2872.html)
+* [SiFIve HiFive1](https://www.sifive.com/boards/hifive1)
+* [ST Micro "Nucleo" F103RB](https://www.st.com/en/evaluation-tools/nucleo-f103rb.html)
+* [ST Micro "Nucleo" F722ZE](https://www.st.com/en/evaluation-tools/nucleo-f722ze.html)
+* [ST Micro "Nucleo" L552ZE](https://www.st.com/en/evaluation-tools/nucleo-l552ze-q.html)
+* [ST Micro STM32F103XX "Bluepill"](https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill)
+* [ST Micro STM32F407 "Discovery"](https://www.st.com/en/evaluation-tools/stm32f4discovery.html)
+* [X9 Pro smartwatch](https://github.com/curtpw/nRF5x-device-reverse-engineering/tree/master/X9-nrf52832-activity-tracker/)
 
-## Supported targets
+For more information, see [this list of boards](https://tinygo.org/microcontrollers/). Pull requests for additional support are welcome!
 
-The following architectures/systems are currently supported:
+## Currently supported features:
 
-  * ARM (Cortex-M)
-  * AVR (Arduino Uno)
-  * Linux
-  * WebAssembly
-
-For more information, see [this list of targets and
-boards](https://tinygo.org/targets/). Pull requests for
-broader support are welcome!
-
-## Analysis and optimizations
-
-The goal is to reduce code size (and increase performance) by performing all
-kinds of whole-program analysis passes. The official Go compiler doesn't do a
-whole lot of analysis (except for escape analysis) because it needs to be fast,
-but embedded programs are necessarily smaller so it becomes practical. And I
-think especially program size can be reduced by a large margin when actually
-trying to optimize for it.
-
-Implemented compiler passes:
-
-  * Analyse which functions are blocking. Blocking functions are functions that
-    call sleep, chan send, etc. Its parents are also blocking.
-  * Analyse whether the scheduler is needed. It is only needed when there are
-    `go` statements for blocking functions.
-  * Analyse whether a given type switch or type assert is possible with
-    [type-based alias analysis](https://en.wikipedia.org/wiki/Alias_analysis#Type-based_alias_analysis).
-    I would like to use flow-based alias analysis in the future, if feasible.
-  * Do basic dead code elimination of functions. This pass makes later passes
-    better and probably improves compile time as well.
-
-## Scope
-
-Goals:
-
-  * Have very small binary sizes. Don't pay for what you don't use.
-  * Support for most common microcontroller boards.
-  * Be usable on the web using WebAssembly.
-  * Good CGo support, with no more overhead than a regular function call.
-  * Support most standard library packages and compile most Go code without
-    modification.
-
-Non-goals:
-
-  * Using more than one core.
-  * Be efficient while using zillions of goroutines. However, good goroutine
-    support is certainly a goal.
-  * Be as fast as `gc`. However, LLVM will probably be better at optimizing
-    certain things so TinyGo might actually turn out to be faster for number
-    crunching.
-  * Be able to compile every Go program out there.
+For a description of currently supported Go language features, please see [https://tinygo.org/lang-support/](https://tinygo.org/lang-support/).
 
 ## Documentation
 
-Documentation is currently maintained on a dedicated web site located at [https://tinygo.org/](https://tinygo.org/).
+Documentation is located on our web site at [https://tinygo.org/](https://tinygo.org/).
 
 You can find the web site code at [https://github.com/tinygo-org/tinygo-site](https://github.com/tinygo-org/tinygo-site).
 
@@ -153,26 +124,41 @@ should arrive fairly quickly (under 1 min): https://invite.slack.golangbridge.or
 
 ## Contributing
 
-Patches are welcome!
+Your contributions are welcome!
 
-If you want to contribute, here are some suggestions:
+Please take a look at our [CONTRIBUTING.md](./CONTRIBUTING.md) document for details.
 
-  * A long tail of small (and large) language features haven't been implemented
-    yet. In almost all cases, the compiler will show a `todo:` error from
-    `compiler/compiler.go` when you try to use it. You can try implementing it,
-    or open a bug report with a small code sample that fails to compile.
-  * Lots of targets/boards are still unsupported. Adding an architecture often
-    requires a few compiler changes, but if the architecture is supported you
-    can try implementing support for a new chip or board in `src/runtime`. For
-    details, see [this wiki entry on adding
-    archs/chips/boards](https://github.com/aykevl/tinygo/wiki/Adding-a-new-board).
-  * Microcontrollers have lots of peripherals and many don't have an
-    implementation yet in the `machine` package. Adding support for new
-    peripherals is very useful.
-  * Just raising bugs for things you'd like to see implemented is also a form of
-    contributing! It helps prioritization.
+## Project Scope
+
+Goals:
+
+* Have very small binary sizes. Don't pay for what you don't use.
+* Support for most common microcontroller boards.
+* Be usable on the web using WebAssembly.
+* Good CGo support, with no more overhead than a regular function call.
+* Support most standard library packages and compile most Go code without modification.
+
+Non-goals:
+
+* Using more than one core.
+* Be efficient while using zillions of goroutines. However, good goroutine support is certainly a goal.
+* Be as fast as `gc`. However, LLVM will probably be better at optimizing certain things so TinyGo might actually turn out to be faster for number crunching.
+* Be able to compile every Go program out there.
+
+## Why this project exists
+
+> We never expected Go to be an embedded language and so its got serious problems...
+
+-- Rob Pike, [GopherCon 2014 Opening Keynote](https://www.youtube.com/watch?v=VoS7DsT1rdM&feature=youtu.be&t=2799)
+
+TinyGo is a project to bring Go to microcontrollers and small systems with a single processor core. It is similar to [emgo](https://github.com/ziutek/emgo) but a major difference is that we want to keep the Go memory model (which implies garbage collection of some sort). Another difference is that TinyGo uses LLVM internally instead of emitting C, which hopefully leads to smaller and more efficient code and certainly leads to more flexibility.
+
+The original reasoning was: if [Python](https://micropython.org/) can run on microcontrollers, then certainly [Go](https://golang.org/) should be able to run on even lower level micros.
 
 ## License
 
-This project is licensed under the BSD 3-clause license, just like the
-[Go project](https://golang.org/LICENSE) itself.
+This project is licensed under the BSD 3-clause license, just like the [Go project](https://golang.org/LICENSE) itself.
+
+Some code has been copied from the LLVM project and is therefore licensed under [a variant of the Apache 2.0 license](http://releases.llvm.org/11.0.0/LICENSE.TXT). This has been clearly indicated in the header of these files.
+
+Some code has been copied and/or ported from Paul Stoffregen's Teensy libraries and is therefore licensed under PJRC's license. This has been clearly indicated in the header of these files.

azure-pipelines.yml

@@ -0,0 +1,88 @@
+# Avoid lengthy LLVM rebuilds on each newly pushed branch. Pull requests will
+# be built anyway.
+trigger:
+- release
+- dev
+
+jobs:
+- job: Build
+  timeoutInMinutes: 240 # 4h
+  pool:
+    vmImage: 'VS2017-Win2016'
+  steps:
+    - task: GoTool@0
+      inputs:
+        version: '1.16'
+    - checkout: self
+      fetchDepth: 1
+    - task: Cache@2
+      displayName: Cache LLVM source
+      inputs:
+        key: llvm-source-11-windows-v1
+        path: llvm-project
+    - task: Bash@3
+      displayName: Download LLVM source
+      inputs:
+        targetType: inline
+        script: make llvm-source
+    - task: CacheBeta@0
+      displayName: Cache LLVM build
+      inputs:
+        key: llvm-build-11-windows-v4
+        path: llvm-build
+    - task: Bash@3
+      displayName: Build LLVM
+      inputs:
+        targetType: inline
+        script: |
+          if [ ! -f llvm-build/lib/liblldELF.a ]
+          then
+            # install dependencies
+            choco install ninja
+            # hack ninja to use fewer jobs
+            echo -e 'C:\\ProgramData\\Chocolatey\\bin\\ninja -j4 %*' > /usr/bin/ninja.bat
+            # build!
+            make llvm-build
+          fi
+    - task: Bash@3
+      displayName: Install QEMU
+      inputs:
+        targetType: inline
+        script: choco install qemu --version=2020.06.12
+    - task: CacheBeta@0
+      displayName: Cache wasi-libc sysroot
+      inputs:
+        key: wasi-libc-sysroot-v4
+        path: lib/wasi-libc/sysroot
+    - task: Bash@3
+      displayName: Build wasi-libc
+      inputs:
+        targetType: inline
+        script: PATH=/usr/bin:$PATH make wasi-libc
+    - task: Bash@3
+      displayName: Test TinyGo
+      inputs:
+        targetType: inline
+        script: |
+          export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
+          unset GOROOT
+          make test
+    - task: Bash@3
+      displayName: Build TinyGo release tarball
+      inputs:
+        targetType: inline
+        script: |
+          export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
+          unset GOROOT
+          make build/release -j4
+    - publish: $(System.DefaultWorkingDirectory)/build/release/tinygo
+      displayName: Publish zip as artifact
+      artifact: tinygo
+    - task: Bash@3
+      displayName: Smoke tests
+      inputs:
+        targetType: inline
+        script: |
+          export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
+          unset GOROOT
+          make smoketest TINYGO=build/tinygo AVR=0 XTENSA=0

builder/ar.go

@@ -0,0 +1,182 @@
+package builder
+
+import (
+	"bytes"
+	"debug/elf"
+	"encoding/binary"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/blakesmith/ar"
+)
+
+// makeArchive creates an arcive for static linking from a list of object files
+// given as a parameter. It is equivalent to the following command:
+//
+//     ar -rcs <archivePath> <objs...>
+func makeArchive(archivePath string, objs []string) error {
+	// Open the archive file.
+	arfile, err := os.Create(archivePath)
+	if err != nil {
+		return err
+	}
+	defer arfile.Close()
+	arwriter := ar.NewWriter(arfile)
+	err = arwriter.WriteGlobalHeader()
+	if err != nil {
+		return &os.PathError{"write ar header", archivePath, err}
+	}
+
+	// Open all object files and read the symbols for the symbol table.
+	symbolTable := []struct {
+		name      string // symbol name
+		fileIndex int    // index into objfiles
+	}{}
+	objfiles := make([]struct {
+		file          *os.File
+		archiveOffset int32
+	}, len(objs))
+	for i, objpath := range objs {
+		objfile, err := os.Open(objpath)
+		if err != nil {
+			return err
+		}
+		objfiles[i].file = objfile
+
+		// Read the symbols and add them to the symbol table.
+		dbg, err := elf.NewFile(objfile)
+		if err != nil {
+			return err
+		}
+		symbols, err := dbg.Symbols()
+		if err != nil {
+			return err
+		}
+		for _, symbol := range symbols {
+			bind := elf.ST_BIND(symbol.Info)
+			if bind != elf.STB_GLOBAL && bind != elf.STB_WEAK {
+				// Don't include local symbols (STB_LOCAL).
+				continue
+			}
+			if elf.ST_TYPE(symbol.Info) != elf.STT_FUNC {
+				// Not a function.
+				// TODO: perhaps globals variables should also be included?
+				continue
+			}
+			// Include in archive.
+			symbolTable = append(symbolTable, struct {
+				name      string
+				fileIndex int
+			}{symbol.Name, i})
+		}
+	}
+
+	// Create the symbol table buffer.
+	// For some (sparse) details on the file format:
+	// https://en.wikipedia.org/wiki/Ar_(Unix)#System_V_(or_GNU)_variant
+	buf := &bytes.Buffer{}
+	binary.Write(buf, binary.BigEndian, int32(len(symbolTable)))
+	for range symbolTable {
+		// This is a placeholder index, it will be updated after all files have
+		// been written to the archive (see the end of this function).
+		err = binary.Write(buf, binary.BigEndian, int32(0))
+		if err != nil {
+			return err
+		}
+	}
+	for _, sym := range symbolTable {
+		_, err := buf.Write([]byte(sym.name + "\x00"))
+		if err != nil {
+			return err
+		}
+	}
+	for buf.Len()%2 != 0 {
+		// The symbol table must be aligned.
+		// This appears to be required by lld.
+		buf.WriteByte(0)
+	}
+
+	// Write the symbol table.
+	err = arwriter.WriteHeader(&ar.Header{
+		Name:    "/",
+		ModTime: time.Unix(0, 0),
+		Uid:     0,
+		Gid:     0,
+		Mode:    0,
+		Size:    int64(buf.Len()),
+	})
+	if err != nil {
+		return err
+	}
+
+	// Keep track of the start of the symbol table.
+	symbolTableStart, err := arfile.Seek(0, os.SEEK_CUR)
+	if err != nil {
+		return err
+	}
+
+	// Write symbol table contents.
+	_, err = arfile.Write(buf.Bytes())
+	if err != nil {
+		return err
+	}
+
+	// Add all object files to the archive.
+	for i, objfile := range objfiles {
+		// Store the start index, for when we'll update the symbol table with
+		// the correct file start indices.
+		offset, err := arfile.Seek(0, os.SEEK_CUR)
+		if err != nil {
+			return err
+		}
+		if int64(int32(offset)) != offset {
+			return errors.New("large archives (4GB+) not supported: " + archivePath)
+		}
+		objfiles[i].archiveOffset = int32(offset)
+
+		// Write the file header.
+		st, err := objfile.file.Stat()
+		if err != nil {
+			return err
+		}
+		err = arwriter.WriteHeader(&ar.Header{
+			Name:    filepath.Base(objfile.file.Name()),
+			ModTime: time.Unix(0, 0),
+			Uid:     0,
+			Gid:     0,
+			Mode:    0644,
+			Size:    st.Size(),
+		})
+		if err != nil {
+			return err
+		}
+
+		// Copy the file contents into the archive.
+		n, err := io.Copy(arwriter, objfile.file)
+		if err != nil {
+			return err
+		}
+		if n != st.Size() {
+			return errors.New("file modified during ar creation: " + archivePath)
+		}
+
+		// File is not needed anymore.
+		objfile.file.Close()
+	}
+
+	// Create symbol indices.
+	indicesBuf := &bytes.Buffer{}
+	for _, sym := range symbolTable {
+		err = binary.Write(indicesBuf, binary.BigEndian, objfiles[sym.fileIndex].archiveOffset)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Overwrite placeholder indices.
+	_, err = arfile.WriteAt(indicesBuf.Bytes(), symbolTableStart+4)
+	return err
+}

builder/build.go

@@ -0,0 +1,867 @@
+// Package builder is the compiler driver of TinyGo. It takes in a package name
+// and an output path, and outputs an executable. It manages the entire
+// compilation pipeline in between.
+package builder
+
+import (
+	"crypto/sha512"
+	"debug/elf"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go/types"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/compiler"
+	"github.com/tinygo-org/tinygo/goenv"
+	"github.com/tinygo-org/tinygo/interp"
+	"github.com/tinygo-org/tinygo/loader"
+	"github.com/tinygo-org/tinygo/stacksize"
+	"github.com/tinygo-org/tinygo/transform"
+	"tinygo.org/x/go-llvm"
+)
+
+// BuildResult is the output of a build. This includes the binary itself and
+// some other metadata that is obtained while building the binary.
+type BuildResult struct {
+	// A path to the output binary. It will be removed after Build returns, so
+	// if it should be kept it must be copied or moved away.
+	Binary string
+
+	// The directory of the main package. This is useful for testing as the test
+	// binary must be run in the directory of the tested package.
+	MainDir string
+}
+
+// packageAction is the struct that is serialized to JSON and hashed, to work as
+// a cache key of compiled packages. It should contain all the information that
+// goes into a compiled package to avoid using stale data.
+//
+// Right now it's still important to include a hash of every import, because a
+// dependency might have a public constant that this package uses and thus this
+// package will need to be recompiled if that constant changes. In the future,
+// the type data should be serialized to disk which can then be used as cache
+// key, avoiding the need for recompiling all dependencies when only the
+// implementation of an imported package changes.
+type packageAction struct {
+	ImportPath      string
+	CompilerVersion int // compiler.Version
+	LLVMVersion     string
+	Config          *compiler.Config
+	CFlags          []string
+	FileHashes      map[string]string // hash of every file that's part of the package
+	Imports         map[string]string // map from imported package to action ID hash
+}
+
+// Build performs a single package to executable Go build. It takes in a package
+// name, an output path, and set of compile options and from that it manages the
+// whole compilation process.
+//
+// The error value may be of type *MultiError. Callers will likely want to check
+// for this case and print such errors individually.
+func Build(pkgName, outpath string, config *compileopts.Config, action func(BuildResult) error) error {
+	// Create a temporary directory for intermediary files.
+	dir, err := ioutil.TempDir("", "tinygo")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(dir)
+
+	compilerConfig := &compiler.Config{
+		Triple:          config.Triple(),
+		CPU:             config.CPU(),
+		Features:        config.Features(),
+		GOOS:            config.GOOS(),
+		GOARCH:          config.GOARCH(),
+		CodeModel:       config.CodeModel(),
+		RelocationModel: config.RelocationModel(),
+
+		Scheduler:          config.Scheduler(),
+		FuncImplementation: config.FuncImplementation(),
+		AutomaticStackSize: config.AutomaticStackSize(),
+		DefaultStackSize:   config.Target.DefaultStackSize,
+		NeedsStackObjects:  config.NeedsStackObjects(),
+		Debug:              config.Debug(),
+	}
+
+	// Load the target machine, which is the LLVM object that contains all
+	// details of a target (alignment restrictions, pointer size, default
+	// address spaces, etc).
+	machine, err := compiler.NewTargetMachine(compilerConfig)
+	if err != nil {
+		return err
+	}
+
+	// Load entire program AST into memory.
+	lprogram, err := loader.Load(config, []string{pkgName}, config.ClangHeaders, types.Config{
+		Sizes: compiler.Sizes(machine),
+	})
+	if err != nil {
+		return err
+	}
+	err = lprogram.Parse()
+	if err != nil {
+		return err
+	}
+
+	// The slice of jobs that orchestrates most of the build.
+	// This is somewhat like an in-memory Makefile with each job being a
+	// Makefile target.
+	var jobs []*compileJob
+
+	// Create the *ssa.Program. This does not yet build the entire SSA of the
+	// program so it's pretty fast and doesn't need to be parallelized.
+	program := lprogram.LoadSSA()
+
+	// Add jobs to compile each package.
+	// Packages that have a cache hit will not be compiled again.
+	var packageJobs []*compileJob
+	packageBitcodePaths := make(map[string]string)
+	packageActionIDs := make(map[string]string)
+	for _, pkg := range lprogram.Sorted() {
+		pkg := pkg // necessary to avoid a race condition
+
+		// Create a cache key: a hash from the action ID below that contains all
+		// the parameters for the build.
+		actionID := packageAction{
+			ImportPath:      pkg.ImportPath,
+			CompilerVersion: compiler.Version,
+			LLVMVersion:     llvm.Version,
+			Config:          compilerConfig,
+			CFlags:          pkg.CFlags,
+			FileHashes:      make(map[string]string, len(pkg.FileHashes)),
+			Imports:         make(map[string]string, len(pkg.Pkg.Imports())),
+		}
+		for filePath, hash := range pkg.FileHashes {
+			actionID.FileHashes[filePath] = hex.EncodeToString(hash)
+		}
+		for _, imported := range pkg.Pkg.Imports() {
+			hash, ok := packageActionIDs[imported.Path()]
+			if !ok {
+				return fmt.Errorf("package %s imports %s but couldn't find dependency", pkg.ImportPath, imported.Path())
+			}
+			actionID.Imports[imported.Path()] = hash
+		}
+		buf, err := json.Marshal(actionID)
+		if err != nil {
+			panic(err) // shouldn't happen
+		}
+		hash := sha512.Sum512_224(buf)
+		packageActionIDs[pkg.ImportPath] = hex.EncodeToString(hash[:])
+
+		// Determine the path of the bitcode file (which is a serialized version
+		// of a LLVM module).
+		cacheDir := goenv.Get("GOCACHE")
+		if cacheDir == "off" {
+			// Use temporary build directory instead, effectively disabling the
+			// build cache.
+			cacheDir = dir
+		}
+		bitcodePath := filepath.Join(cacheDir, "pkg-"+hex.EncodeToString(hash[:])+".bc")
+		packageBitcodePaths[pkg.ImportPath] = bitcodePath
+
+		// Check whether this package has been compiled before, and if so don't
+		// compile it again.
+		if _, err := os.Stat(bitcodePath); err == nil {
+			// Already cached, don't recreate this package.
+			continue
+		}
+
+		// The package has not yet been compiled, so create a job to do so.
+		job := &compileJob{
+			description: "compile package " + pkg.ImportPath,
+			run: func() error {
+				// Compile AST to IR. The compiler.CompilePackage function will
+				// build the SSA as needed.
+				mod, errs := compiler.CompilePackage(pkg.ImportPath, pkg, program.Package(pkg.Pkg), machine, compilerConfig, config.DumpSSA())
+				if errs != nil {
+					return newMultiError(errs)
+				}
+				if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
+					return errors.New("verification error after compiling package " + pkg.ImportPath)
+				}
+
+				// Serialize the LLVM module as a bitcode file.
+				// Write to a temporary path that is renamed to the destination
+				// file to avoid race conditions with other TinyGo invocatiosn
+				// that might also be compiling this package at the same time.
+				f, err := ioutil.TempFile(filepath.Dir(bitcodePath), filepath.Base(bitcodePath))
+				if err != nil {
+					return err
+				}
+				if runtime.GOOS == "windows" {
+					// Work around a problem on Windows.
+					// For some reason, WriteBitcodeToFile causes TinyGo to
+					// exit with the following message:
+					//   LLVM ERROR: IO failure on output stream: Bad file descriptor
+					buf := llvm.WriteBitcodeToMemoryBuffer(mod)
+					defer buf.Dispose()
+					_, err = f.Write(buf.Bytes())
+				} else {
+					// Otherwise, write bitcode directly to the file (probably
+					// faster).
+					err = llvm.WriteBitcodeToFile(mod, f)
+				}
+				if err != nil {
+					// WriteBitcodeToFile doesn't produce a useful error on its
+					// own, so create a somewhat useful error message here.
+					return fmt.Errorf("failed to write bitcode for package %s to file %s", pkg.ImportPath, bitcodePath)
+				}
+				err = f.Close()
+				if err != nil {
+					return err
+				}
+				return os.Rename(f.Name(), bitcodePath)
+			},
+		}
+		jobs = append(jobs, job)
+		packageJobs = append(packageJobs, job)
+	}
+
+	// Add job that links and optimizes all packages together.
+	var mod llvm.Module
+	var stackSizeLoads []string
+	programJob := &compileJob{
+		description:  "link+optimize packages (LTO)",
+		dependencies: packageJobs,
+		run: func() error {
+			// Load and link all the bitcode files. This does not yet optimize
+			// anything, it only links the bitcode files together.
+			ctx := llvm.NewContext()
+			mod = ctx.NewModule("")
+			for _, pkg := range lprogram.Sorted() {
+				pkgMod, err := ctx.ParseBitcodeFile(packageBitcodePaths[pkg.ImportPath])
+				if err != nil {
+					return fmt.Errorf("failed to load bitcode file: %w", err)
+				}
+				err = llvm.LinkModules(mod, pkgMod)
+				if err != nil {
+					return fmt.Errorf("failed to link module: %w", err)
+				}
+			}
+
+			// Create runtime.initAll function that calls the runtime
+			// initializer of each package.
+			llvmInitFn := mod.NamedFunction("runtime.initAll")
+			llvmInitFn.SetLinkage(llvm.InternalLinkage)
+			llvmInitFn.SetUnnamedAddr(true)
+			llvmInitFn.Param(0).SetName("context")
+			llvmInitFn.Param(1).SetName("parentHandle")
+			block := mod.Context().AddBasicBlock(llvmInitFn, "entry")
+			irbuilder := mod.Context().NewBuilder()
+			defer irbuilder.Dispose()
+			irbuilder.SetInsertPointAtEnd(block)
+			i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
+			for _, pkg := range lprogram.Sorted() {
+				pkgInit := mod.NamedFunction(pkg.Pkg.Path() + ".init")
+				if pkgInit.IsNil() {
+					panic("init not found for " + pkg.Pkg.Path())
+				}
+				irbuilder.CreateCall(pkgInit, []llvm.Value{llvm.Undef(i8ptrType), llvm.Undef(i8ptrType)}, "")
+			}
+			irbuilder.CreateRetVoid()
+
+			// After linking, functions should (as far as possible) be set to
+			// private linkage or internal linkage. The compiler package marks
+			// non-exported functions by setting the visibility to hidden or
+			// (for thunks) to linkonce_odr linkage. Change the linkage here to
+			// internal to benefit much more from interprocedural optimizations.
+			for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+				if fn.Visibility() == llvm.HiddenVisibility {
+					fn.SetVisibility(llvm.DefaultVisibility)
+					fn.SetLinkage(llvm.InternalLinkage)
+				} else if fn.Linkage() == llvm.LinkOnceODRLinkage {
+					fn.SetLinkage(llvm.InternalLinkage)
+				}
+			}
+
+			// Do the same for globals.
+			for global := mod.FirstGlobal(); !global.IsNil(); global = llvm.NextGlobal(global) {
+				if global.Visibility() == llvm.HiddenVisibility {
+					global.SetVisibility(llvm.DefaultVisibility)
+					global.SetLinkage(llvm.InternalLinkage)
+				} else if global.Linkage() == llvm.LinkOnceODRLinkage {
+					global.SetLinkage(llvm.InternalLinkage)
+				}
+			}
+
+			if config.Options.PrintIR {
+				fmt.Println("; Generated LLVM IR:")
+				fmt.Println(mod.String())
+			}
+
+			// Run all optimization passes, which are much more effective now
+			// that the optimizer can see the whole program at once.
+			err := optimizeProgram(mod, config)
+			if err != nil {
+				return err
+			}
+
+			// Make sure stack sizes are loaded from a separate section so they can be
+			// modified after linking.
+			if config.AutomaticStackSize() {
+				stackSizeLoads = transform.CreateStackSizeLoads(mod, config)
+			}
+			return nil
+		},
+	}
+	jobs = append(jobs, programJob)
+
+	// Check whether we only need to create an object file.
+	// If so, we don't need to link anything and will be finished quickly.
+	outext := filepath.Ext(outpath)
+	if outext == ".o" || outext == ".bc" || outext == ".ll" {
+		// Run jobs to produce the LLVM module.
+		err := runJobs(jobs)
+		if err != nil {
+			return err
+		}
+		// Generate output.
+		switch outext {
+		case ".o":
+			llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
+			if err != nil {
+				return err
+			}
+			return ioutil.WriteFile(outpath, llvmBuf.Bytes(), 0666)
+		case ".bc":
+			data := llvm.WriteBitcodeToMemoryBuffer(mod).Bytes()
+			return ioutil.WriteFile(outpath, data, 0666)
+		case ".ll":
+			data := []byte(mod.String())
+			return ioutil.WriteFile(outpath, data, 0666)
+		default:
+			panic("unreachable")
+		}
+	}
+
+	// Act as a compiler driver, as we need to produce a complete executable.
+	// First add all jobs necessary to build this object file, then afterwards
+	// run all jobs in parallel as far as possible.
+
+	// Add job to write the output object file.
+	objfile := filepath.Join(dir, "main.o")
+	outputObjectFileJob := &compileJob{
+		description:  "generate output file",
+		dependencies: []*compileJob{programJob},
+		run: func() error {
+			llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
+			if err != nil {
+				return err
+			}
+			return ioutil.WriteFile(objfile, llvmBuf.Bytes(), 0666)
+		},
+	}
+	jobs = append(jobs, outputObjectFileJob)
+
+	// Prepare link command.
+	linkerDependencies := []*compileJob{outputObjectFileJob}
+	executable := filepath.Join(dir, "main")
+	tmppath := executable // final file
+	ldflags := append(config.LDFlags(), "-o", executable, objfile)
+
+	// Add compiler-rt dependency if needed. Usually this is a simple load from
+	// a cache.
+	if config.Target.RTLib == "compiler-rt" {
+		path, job, err := CompilerRT.load(config.Triple(), config.CPU(), dir)
+		if err != nil {
+			return err
+		}
+		if job != nil {
+			// The library was not loaded from cache so needs to be compiled
+			// (and then stored in the cache).
+			jobs = append(jobs, job.dependencies...)
+			jobs = append(jobs, job)
+			linkerDependencies = append(linkerDependencies, job)
+		}
+		ldflags = append(ldflags, path)
+	}
+
+	// Add libc dependency if needed.
+	root := goenv.Get("TINYGOROOT")
+	switch config.Target.Libc {
+	case "picolibc":
+		path, job, err := Picolibc.load(config.Triple(), config.CPU(), dir)
+		if err != nil {
+			return err
+		}
+		if job != nil {
+			// The library needs to be compiled (cache miss).
+			jobs = append(jobs, job.dependencies...)
+			jobs = append(jobs, job)
+			linkerDependencies = append(linkerDependencies, job)
+		}
+		ldflags = append(ldflags, path)
+	case "wasi-libc":
+		path := filepath.Join(root, "lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a")
+		if _, err := os.Stat(path); os.IsNotExist(err) {
+			return errors.New("could not find wasi-libc, perhaps you need to run `make wasi-libc`?")
+		}
+		ldflags = append(ldflags, path)
+	case "":
+		// no library specified, so nothing to do
+	default:
+		return fmt.Errorf("unknown libc: %s", config.Target.Libc)
+	}
+
+	// Add jobs to compile extra files. These files are in C or assembly and
+	// contain things like the interrupt vector table and low level operations
+	// such as stack switching.
+	for i, path := range config.ExtraFiles() {
+		abspath := filepath.Join(root, path)
+		outpath := filepath.Join(dir, "extra-"+strconv.Itoa(i)+"-"+filepath.Base(path)+".o")
+		job := &compileJob{
+			description: "compile extra file " + path,
+			run: func() error {
+				err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, abspath)...)
+				if err != nil {
+					return &commandError{"failed to build", path, err}
+				}
+				return nil
+			},
+		}
+		jobs = append(jobs, job)
+		linkerDependencies = append(linkerDependencies, job)
+		ldflags = append(ldflags, outpath)
+	}
+
+	// Add jobs to compile C files in all packages. This is part of CGo.
+	// TODO: do this as part of building the package to be able to link the
+	// bitcode files together.
+	for i, pkg := range lprogram.Sorted() {
+		for j, filename := range pkg.CFiles {
+			file := filepath.Join(pkg.Dir, filename)
+			outpath := filepath.Join(dir, "pkg"+strconv.Itoa(i)+"."+strconv.Itoa(j)+"-"+filepath.Base(file)+".o")
+			job := &compileJob{
+				description: "compile CGo file " + file,
+				run: func() error {
+					err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, file)...)
+					if err != nil {
+						return &commandError{"failed to build", file, err}
+					}
+					return nil
+				},
+			}
+			jobs = append(jobs, job)
+			linkerDependencies = append(linkerDependencies, job)
+			ldflags = append(ldflags, outpath)
+		}
+	}
+
+	// Linker flags from CGo lines:
+	//     #cgo LDFLAGS: foo
+	if len(lprogram.LDFlags) > 0 {
+		ldflags = append(ldflags, lprogram.LDFlags...)
+	}
+
+	// Create a linker job, which links all object files together and does some
+	// extra stuff that can only be done after linking.
+	jobs = append(jobs, &compileJob{
+		description:  "link",
+		dependencies: linkerDependencies,
+		run: func() error {
+			err = link(config.Target.Linker, ldflags...)
+			if err != nil {
+				return &commandError{"failed to link", executable, err}
+			}
+
+			var calculatedStacks []string
+			var stackSizes map[string]functionStackSize
+			if config.Options.PrintStacks || config.AutomaticStackSize() {
+				// Try to determine stack sizes at compile time.
+				// Don't do this by default as it usually doesn't work on
+				// unsupported architectures.
+				calculatedStacks, stackSizes, err = determineStackSizes(mod, executable)
+				if err != nil {
+					return err
+				}
+			}
+			if config.AutomaticStackSize() {
+				// Modify the .tinygo_stacksizes section that contains a stack size
+				// for each goroutine.
+				err = modifyStackSizes(executable, stackSizeLoads, stackSizes)
+				if err != nil {
+					return fmt.Errorf("could not modify stack sizes: %w", err)
+				}
+			}
+
+			if config.Options.PrintSizes == "short" || config.Options.PrintSizes == "full" {
+				sizes, err := loadProgramSize(executable)
+				if err != nil {
+					return err
+				}
+				if config.Options.PrintSizes == "short" {
+					fmt.Printf("   code    data     bss |   flash     ram\n")
+					fmt.Printf("%7d %7d %7d | %7d %7d\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
+				} else {
+					fmt.Printf("   code  rodata    data     bss |   flash     ram | package\n")
+					for _, name := range sizes.sortedPackageNames() {
+						pkgSize := sizes.Packages[name]
+						fmt.Printf("%7d %7d %7d %7d | %7d %7d | %s\n", pkgSize.Code, pkgSize.ROData, pkgSize.Data, pkgSize.BSS, pkgSize.Flash(), pkgSize.RAM(), name)
+					}
+					fmt.Printf("%7d %7d %7d %7d | %7d %7d | (sum)\n", sizes.Sum.Code, sizes.Sum.ROData, sizes.Sum.Data, sizes.Sum.BSS, sizes.Sum.Flash(), sizes.Sum.RAM())
+					fmt.Printf("%7d       - %7d %7d | %7d %7d | (all)\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
+				}
+			}
+
+			// Print goroutine stack sizes, as far as possible.
+			if config.Options.PrintStacks {
+				printStacks(calculatedStacks, stackSizes)
+			}
+
+			return nil
+		},
+	})
+
+	// Run all jobs to compile and link the program.
+	// Do this now (instead of after elf-to-hex and similar conversions) as it
+	// is simpler and cannot be parallelized.
+	err = runJobs(jobs)
+	if err != nil {
+		return err
+	}
+
+	// Get an Intel .hex file or .bin file from the .elf file.
+	outputBinaryFormat := config.BinaryFormat(outext)
+	switch outputBinaryFormat {
+	case "elf":
+		// do nothing, file is already in ELF format
+	case "hex", "bin":
+		// Extract raw binary, either encoding it as a hex file or as a raw
+		// firmware file.
+		tmppath = filepath.Join(dir, "main"+outext)
+		err := objcopy(executable, tmppath, outputBinaryFormat)
+		if err != nil {
+			return err
+		}
+	case "uf2":
+		// Get UF2 from the .elf file.
+		tmppath = filepath.Join(dir, "main"+outext)
+		err := convertELFFileToUF2File(executable, tmppath, config.Target.UF2FamilyID)
+		if err != nil {
+			return err
+		}
+	case "esp32", "esp8266":
+		// Special format for the ESP family of chips (parsed by the ROM
+		// bootloader).
+		tmppath = filepath.Join(dir, "main"+outext)
+		err := makeESPFirmareImage(executable, tmppath, outputBinaryFormat)
+		if err != nil {
+			return err
+		}
+	default:
+		return fmt.Errorf("unknown output binary format: %s", outputBinaryFormat)
+	}
+	return action(BuildResult{
+		Binary:  tmppath,
+		MainDir: lprogram.MainPkg().Dir,
+	})
+}
+
+// optimizeProgram runs a series of optimizations and transformations that are
+// needed to convert a program to its final form. Some transformations are not
+// optional and must be run as the compiler expects them to run.
+func optimizeProgram(mod llvm.Module, config *compileopts.Config) error {
+	err := interp.Run(mod, config.DumpSSA())
+	if err != nil {
+		return err
+	}
+	if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
+		return errors.New("verification error after interpreting runtime.initAll")
+	}
+
+	if config.GOOS() != "darwin" {
+		transform.ApplyFunctionSections(mod) // -ffunction-sections
+	}
+
+	// Browsers cannot handle external functions that have type i64 because it
+	// cannot be represented exactly in JavaScript (JS only has doubles). To
+	// keep functions interoperable, pass int64 types as pointers to
+	// stack-allocated values.
+	// Use -wasm-abi=generic to disable this behaviour.
+	if config.WasmAbi() == "js" {
+		err := transform.ExternalInt64AsPtr(mod)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Optimization levels here are roughly the same as Clang, but probably not
+	// exactly.
+	var errs []error
+	switch config.Options.Opt {
+	case "none", "0":
+		errs = transform.Optimize(mod, config, 0, 0, 0) // -O0
+	case "1":
+		errs = transform.Optimize(mod, config, 1, 0, 0) // -O1
+	case "2":
+		errs = transform.Optimize(mod, config, 2, 0, 225) // -O2
+	case "s":
+		errs = transform.Optimize(mod, config, 2, 1, 225) // -Os
+	case "z":
+		errs = transform.Optimize(mod, config, 2, 2, 5) // -Oz, default
+	default:
+		return errors.New("unknown optimization level: -opt=" + config.Options.Opt)
+	}
+	if len(errs) > 0 {
+		return newMultiError(errs)
+	}
+	if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
+		return errors.New("verification failure after LLVM optimization passes")
+	}
+
+	// LLVM 11 by default tries to emit tail calls (even with the target feature
+	// disabled) unless it is explicitly disabled with a function attribute.
+	// This is a problem, as it tries to emit them and prints an error when it
+	// can't with this feature disabled.
+	// Because as of september 2020 tail calls are not yet widely supported,
+	// they need to be disabled until they are widely supported (at which point
+	// the +tail-call target feautre can be set).
+	if strings.HasPrefix(config.Triple(), "wasm") {
+		transform.DisableTailCalls(mod)
+	}
+
+	return nil
+}
+
+// functionStackSizes keeps stack size information about a single function
+// (usually a goroutine).
+type functionStackSize struct {
+	humanName        string
+	stackSize        uint64
+	stackSizeType    stacksize.SizeType
+	missingStackSize *stacksize.CallNode
+}
+
+// determineStackSizes tries to determine the stack sizes of all started
+// goroutines and of the reset vector. The LLVM module is necessary to find
+// functions that call a function pointer.
+func determineStackSizes(mod llvm.Module, executable string) ([]string, map[string]functionStackSize, error) {
+	var callsIndirectFunction []string
+	gowrappers := []string{}
+	gowrapperNames := make(map[string]string)
+	for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+		// Determine which functions call a function pointer.
+		for bb := fn.FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+			for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+				if inst.IsACallInst().IsNil() {
+					continue
+				}
+				if callee := inst.CalledValue(); callee.IsAFunction().IsNil() && callee.IsAInlineAsm().IsNil() {
+					callsIndirectFunction = append(callsIndirectFunction, fn.Name())
+				}
+			}
+		}
+
+		// Get a list of "go wrappers", small wrapper functions that decode
+		// parameters when starting a new goroutine.
+		attr := fn.GetStringAttributeAtIndex(-1, "tinygo-gowrapper")
+		if !attr.IsNil() {
+			gowrappers = append(gowrappers, fn.Name())
+			gowrapperNames[fn.Name()] = attr.GetStringValue()
+		}
+	}
+	sort.Strings(gowrappers)
+
+	// Load the ELF binary.
+	f, err := elf.Open(executable)
+	if err != nil {
+		return nil, nil, fmt.Errorf("could not load executable for stack size analysis: %w", err)
+	}
+	defer f.Close()
+
+	// Determine the frame size of each function (if available) and the callgraph.
+	functions, err := stacksize.CallGraph(f, callsIndirectFunction)
+	if err != nil {
+		return nil, nil, fmt.Errorf("could not parse executable for stack size analysis: %w", err)
+	}
+
+	// Goroutines need to be started and finished and take up some stack space
+	// that way. This can be measured by measuing the stack size of
+	// tinygo_startTask.
+	if numFuncs := len(functions["tinygo_startTask"]); numFuncs != 1 {
+		return nil, nil, fmt.Errorf("expected exactly one definition of tinygo_startTask, got %d", numFuncs)
+	}
+	baseStackSize, baseStackSizeType, baseStackSizeFailedAt := functions["tinygo_startTask"][0].StackSize()
+
+	sizes := make(map[string]functionStackSize)
+
+	// Add the reset handler function, for convenience. The reset handler runs
+	// startup code and the scheduler. The listed stack size is not the full
+	// stack size: interrupts are not counted.
+	var resetFunction string
+	switch f.Machine {
+	case elf.EM_ARM:
+		// Note: all interrupts happen on this stack so the real size is bigger.
+		resetFunction = "Reset_Handler"
+	}
+	if resetFunction != "" {
+		funcs := functions[resetFunction]
+		if len(funcs) != 1 {
+			return nil, nil, fmt.Errorf("expected exactly one definition of %s in the callgraph, found %d", resetFunction, len(funcs))
+		}
+		stackSize, stackSizeType, missingStackSize := funcs[0].StackSize()
+		sizes[resetFunction] = functionStackSize{
+			stackSize:        stackSize,
+			stackSizeType:    stackSizeType,
+			missingStackSize: missingStackSize,
+			humanName:        resetFunction,
+		}
+	}
+
+	// Add all goroutine wrapper functions.
+	for _, name := range gowrappers {
+		funcs := functions[name]
+		if len(funcs) != 1 {
+			return nil, nil, fmt.Errorf("expected exactly one definition of %s in the callgraph, found %d", name, len(funcs))
+		}
+		humanName := gowrapperNames[name]
+		if humanName == "" {
+			humanName = name // fallback
+		}
+		stackSize, stackSizeType, missingStackSize := funcs[0].StackSize()
+		if baseStackSizeType != stacksize.Bounded {
+			// It was not possible to determine the stack size at compile time
+			// because tinygo_startTask does not have a fixed stack size. This
+			// can happen when using -opt=1.
+			stackSizeType = baseStackSizeType
+			missingStackSize = baseStackSizeFailedAt
+		} else if stackSize < baseStackSize {
+			// This goroutine has a very small stack, but still needs to fit all
+			// registers to start and suspend the goroutine. Otherwise a stack
+			// overflow will occur even before the goroutine is started.
+			stackSize = baseStackSize
+		}
+		sizes[name] = functionStackSize{
+			stackSize:        stackSize,
+			stackSizeType:    stackSizeType,
+			missingStackSize: missingStackSize,
+			humanName:        humanName,
+		}
+	}
+
+	if resetFunction != "" {
+		return append([]string{resetFunction}, gowrappers...), sizes, nil
+	}
+	return gowrappers, sizes, nil
+}
+
+// modifyStackSizes modifies the .tinygo_stacksizes section with the updated
+// stack size information. Before this modification, all stack sizes in the
+// section assume the default stack size (which is relatively big).
+func modifyStackSizes(executable string, stackSizeLoads []string, stackSizes map[string]functionStackSize) error {
+	fp, err := os.OpenFile(executable, os.O_RDWR, 0)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+
+	elfFile, err := elf.NewFile(fp)
+	if err != nil {
+		return err
+	}
+
+	section := elfFile.Section(".tinygo_stacksizes")
+	if section == nil {
+		return errors.New("could not find .tinygo_stacksizes section")
+	}
+
+	if section.Size != section.FileSize {
+		// Sanity check.
+		return fmt.Errorf("expected .tinygo_stacksizes to have identical size and file size, got %d and %d", section.Size, section.FileSize)
+	}
+
+	// Read all goroutine stack sizes.
+	data := make([]byte, section.Size)
+	_, err = fp.ReadAt(data, int64(section.Offset))
+	if err != nil {
+		return err
+	}
+
+	if len(stackSizeLoads)*4 != len(data) {
+		// Note: while AVR should use 2 byte stack sizes, even 64-bit platforms
+		// should probably stick to 4 byte stack sizes as a larger than 4GB
+		// stack doesn't make much sense.
+		return errors.New("expected 4 byte stack sizes")
+	}
+
+	// Modify goroutine stack sizes with a compile-time known worst case stack
+	// size.
+	for i, name := range stackSizeLoads {
+		fn, ok := stackSizes[name]
+		if !ok {
+			return fmt.Errorf("could not find symbol %s in ELF file", name)
+		}
+		if fn.stackSizeType == stacksize.Bounded {
+			stackSize := uint32(fn.stackSize)
+
+			// Adding 4 for the stack canary. Even though the size may be
+			// automatically determined, stack overflow checking is still
+			// important as the stack size cannot be determined for all
+			// goroutines.
+			stackSize += 4
+
+			// Add stack size used by interrupts.
+			switch elfFile.Machine {
+			case elf.EM_ARM:
+				// On Cortex-M (assumed here), this stack size is 8 words or 32
+				// bytes. This is only to store the registers that the interrupt
+				// may modify, the interrupt will switch to the interrupt stack
+				// (MSP).
+				// Some background:
+				// https://interrupt.memfault.com/blog/cortex-m-rtos-context-switching
+				stackSize += 32
+			}
+
+			// Finally write the stack size to the binary.
+			binary.LittleEndian.PutUint32(data[i*4:], stackSize)
+		}
+	}
+
+	// Write back the modified stack sizes.
+	_, err = fp.WriteAt(data, int64(section.Offset))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// printStacks prints the maximum stack depth for functions that are started as
+// goroutines. Stack sizes cannot always be determined statically, in particular
+// recursive functions and functions that call interface methods or function
+// pointers may have an unknown stack depth (depending on what the optimizer
+// manages to optimize away).
+//
+// It might print something like the following:
+//
+//     function                         stack usage (in bytes)
+//     Reset_Handler                    316
+//     examples/blinky2.led1            92
+//     runtime.run$1                    300
+func printStacks(calculatedStacks []string, stackSizes map[string]functionStackSize) {
+	// Print the sizes of all stacks.
+	fmt.Printf("%-32s %s\n", "function", "stack usage (in bytes)")
+	for _, name := range calculatedStacks {
+		fn := stackSizes[name]
+		switch fn.stackSizeType {
+		case stacksize.Bounded:
+			fmt.Printf("%-32s %d\n", fn.humanName, fn.stackSize)
+		case stacksize.Unknown:
+			fmt.Printf("%-32s unknown, %s does not have stack frame information\n", fn.humanName, fn.missingStackSize)
+		case stacksize.Recursive:
+			fmt.Printf("%-32s recursive, %s may call itself\n", fn.humanName, fn.missingStackSize)
+		case stacksize.IndirectCall:
+			fmt.Printf("%-32s unknown, %s calls a function pointer\n", fn.humanName, fn.missingStackSize)
+		}
+	}
+}

builder/buildcache.go

@@ -1,18 +1,13 @@
-package main
+package builder
 
 import (
 	"io"
 	"os"
 	"path/filepath"
 	"time"
-)
 
-// Get the cache directory, usually ~/.cache/tinygo
-func cacheDir() string {
-	home := getHomeDir()
-	dir := filepath.Join(home, ".cache", "tinygo")
-	return dir
-}
+	"github.com/tinygo-org/tinygo/goenv"
+)
 
 // Return the newest timestamp of all the file paths passed in. Used to check
 // for stale caches.
@@ -35,12 +30,8 @@ func cacheTimestamp(paths []string) (time.Time, error) {
 // Try to load a given file from the cache. Return "", nil if no cached file can
 // be found (or the file is stale), return the absolute path if there is a cache
 // and return an error on I/O errors.
-//
-// TODO: the configKey is currently ignored. It is supposed to be used as extra
-// data for the cache key, like the compiler version and arguments.
-func cacheLoad(name, configKey string, sourceFiles []string) (string, error) {
-	dir := cacheDir()
-	cachepath := filepath.Join(dir, name)
+func cacheLoad(name string, sourceFiles []string) (string, error) {
+	cachepath := filepath.Join(goenv.Get("GOCACHE"), name)
 	cacheStat, err := os.Stat(cachepath)
 	if os.IsNotExist(err) {
 		return "", nil // does not exist
@@ -64,9 +55,7 @@ func cacheLoad(name, configKey string, sourceFiles []string) (string, error) {
 
 // Store the file located at tmppath in the cache with the given name. The
 // tmppath may or may not be gone afterwards.
-//
-// Note: the configKey is ignored, see cacheLoad.
-func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string, error) {
+func cacheStore(tmppath, name string, sourceFiles []string) (string, error) {
 	// get the last modified time
 	if len(sourceFiles) == 0 {
 		panic("cache: no source files")
@@ -74,35 +63,43 @@ func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string,
 
 	// TODO: check the config key
 
-	dir := cacheDir()
+	dir := goenv.Get("GOCACHE")
 	err := os.MkdirAll(dir, 0777)
 	if err != nil {
 		return "", err
 	}
 	cachepath := filepath.Join(dir, name)
-	err = os.Rename(tmppath, cachepath)
+	err = copyFile(tmppath, cachepath)
 	if err != nil {
-		inf, err := os.Open(tmppath)
-		if err != nil {
-			return "", err
-		}
-		defer inf.Close()
-		outf, err := os.Create(cachepath + ".tmp")
-		if err != nil {
-			return "", err
-		}
-
-		_, err = io.Copy(outf, inf)
-		if err != nil {
-			return "", err
-		}
-
-		err = os.Rename(cachepath+".tmp", cachepath)
-		if err != nil {
-			return "", err
-		}
-
-		return cachepath, outf.Close()
+		return "", err
 	}
 	return cachepath, nil
 }
+
+// copyFile copies the given file from src to dst. It can copy over
+// a possibly already existing file at the destination.
+func copyFile(src, dst string) error {
+	inf, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer inf.Close()
+	outpath := dst + ".tmp"
+	outf, err := os.Create(outpath)
+	if err != nil {
+		return err
+	}
+
+	_, err = io.Copy(outf, inf)
+	if err != nil {
+		os.Remove(outpath)
+		return err
+	}
+
+	err = outf.Close()
+	if err != nil {
+		return err
+	}
+
+	return os.Rename(dst+".tmp", dst)
+}

builder/builtins.go

@@ -1,10 +1,6 @@
-package main
+package builder
 
 import (
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"path/filepath"
 	"strings"
 )
 
@@ -155,66 +151,20 @@ var aeabiBuiltins = []string{
 	"arm/aeabi_uldivmod.S",
 }
 
-func builtinFiles(target string) []string {
-	builtins := append([]string{}, genericBuiltins...) // copy genericBuiltins
-	if target[:3] == "arm" {
-		builtins = append(builtins, aeabiBuiltins...)
-	}
-	return builtins
-}
-
-// Get the builtins archive, possibly generating it as needed.
-func loadBuiltins(target string) (path string, err error) {
-	outfile := "librt-" + target + ".a"
-	builtinsDir := filepath.Join(sourceDir(), "lib", "compiler-rt", "lib", "builtins")
-
-	builtins := builtinFiles(target)
-	srcs := make([]string, len(builtins))
-	for i, name := range builtins {
-		srcs[i] = filepath.Join(builtinsDir, name)
-	}
-
-	if path, err := cacheLoad(outfile, commands["clang"], srcs); path != "" || err != nil {
-		return path, err
-	}
-
-	dir, err := ioutil.TempDir("", "tinygo-builtins")
-	if err != nil {
-		return "", err
-	}
-	defer os.RemoveAll(dir)
-
-	// Compile all builtins.
-	// TODO: use builtins optimized for a given target if available.
-	objs := make([]string, 0, len(builtins))
-	for _, name := range builtins {
-		objname := name
-		if strings.LastIndexByte(objname, '/') >= 0 {
-			objname = objname[strings.LastIndexByte(objname, '/'):]
+// CompilerRT is a library with symbols required by programs compiled with LLVM.
+// These symbols are for operations that cannot be emitted with a single
+// instruction or a short sequence of instructions for that target.
+//
+// For more information, see: https://compiler-rt.llvm.org/
+var CompilerRT = Library{
+	name:      "compiler-rt",
+	cflags:    func() []string { return []string{"-Werror", "-Wall", "-std=c11", "-nostdlibinc"} },
+	sourceDir: "lib/compiler-rt/lib/builtins",
+	sources: func(target string) []string {
+		builtins := append([]string{}, genericBuiltins...) // copy genericBuiltins
+		if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
+			builtins = append(builtins, aeabiBuiltins...)
 		}
-		objpath := filepath.Join(dir, objname+".o")
-		objs = append(objs, objpath)
-		srcpath := filepath.Join(builtinsDir, name)
-		cmd := exec.Command(commands["clang"], "-c", "-Oz", "-g", "-Werror", "-Wall", "-std=c11", "-fshort-enums", "-nostdlibinc", "-ffunction-sections", "-fdata-sections", "--target="+target, "-o", objpath, srcpath)
-		cmd.Stdout = os.Stdout
-		cmd.Stderr = os.Stderr
-		cmd.Dir = dir
-		err = cmd.Run()
-		if err != nil {
-			return "", err
-		}
-	}
-
-	// Put all builtins in an archive to link as a static library.
-	arpath := filepath.Join(dir, "librt.a")
-	cmd := exec.Command(commands["ar"], append([]string{"cr", arpath}, objs...)...)
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	cmd.Dir = dir
-	err = cmd.Run()
-	if err != nil {
-		return "", err
-	}
-
-	return cacheStore(arpath, outfile, commands["clang"], srcs)
+		return builtins
+	},
 }

builder/cc1as.cpp

@@ -0,0 +1,513 @@
+// +build byollvm
+
+//===-- cc1as.cpp - Clang Assembler  --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the entry point to the clang -cc1as functionality, which implements
+// the direct interface to the LLVM MC based assembler.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticOptions.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/Options.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Frontend/Utils.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCParser/MCAsmParser.h"
+#include "llvm/MC/MCParser/MCTargetAsmParser.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCTargetOptions.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Option/OptTable.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+#include <memory>
+#include <system_error>
+using namespace clang;
+using namespace clang::driver;
+using namespace clang::driver::options;
+using namespace llvm;
+using namespace llvm::opt;
+
+#include "cc1as.h"
+
+bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
+                                         ArrayRef<const char *> Argv,
+                                         DiagnosticsEngine &Diags) {
+  bool Success = true;
+
+  // Parse the arguments.
+  const OptTable &OptTbl = getDriverOptTable();
+
+  const unsigned IncludedFlagsBitmask = options::CC1AsOption;
+  unsigned MissingArgIndex, MissingArgCount;
+  InputArgList Args = OptTbl.ParseArgs(Argv, MissingArgIndex, MissingArgCount,
+                                       IncludedFlagsBitmask);
+
+  // Check for missing argument error.
+  if (MissingArgCount) {
+    Diags.Report(diag::err_drv_missing_argument)
+        << Args.getArgString(MissingArgIndex) << MissingArgCount;
+    Success = false;
+  }
+
+  // Issue errors on unknown arguments.
+  for (const Arg *A : Args.filtered(OPT_UNKNOWN)) {
+    auto ArgString = A->getAsString(Args);
+    std::string Nearest;
+    if (OptTbl.findNearest(ArgString, Nearest, IncludedFlagsBitmask) > 1)
+      Diags.Report(diag::err_drv_unknown_argument) << ArgString;
+    else
+      Diags.Report(diag::err_drv_unknown_argument_with_suggestion)
+          << ArgString << Nearest;
+    Success = false;
+  }
+
+  // Construct the invocation.
+
+  // Target Options
+  Opts.Triple = llvm::Triple::normalize(Args.getLastArgValue(OPT_triple));
+  Opts.CPU = std::string(Args.getLastArgValue(OPT_target_cpu));
+  Opts.Features = Args.getAllArgValues(OPT_target_feature);
+
+  // Use the default target triple if unspecified.
+  if (Opts.Triple.empty())
+    Opts.Triple = llvm::sys::getDefaultTargetTriple();
+
+  // Language Options
+  Opts.IncludePaths = Args.getAllArgValues(OPT_I);
+  Opts.NoInitialTextSection = Args.hasArg(OPT_n);
+  Opts.SaveTemporaryLabels = Args.hasArg(OPT_msave_temp_labels);
+  // Any DebugInfoKind implies GenDwarfForAssembly.
+  Opts.GenDwarfForAssembly = Args.hasArg(OPT_debug_info_kind_EQ);
+
+  if (const Arg *A = Args.getLastArg(OPT_compress_debug_sections,
+                                     OPT_compress_debug_sections_EQ)) {
+    if (A->getOption().getID() == OPT_compress_debug_sections) {
+      // TODO: be more clever about the compression type auto-detection
+      Opts.CompressDebugSections = llvm::DebugCompressionType::GNU;
+    } else {
+      Opts.CompressDebugSections =
+          llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue())
+              .Case("none", llvm::DebugCompressionType::None)
+              .Case("zlib", llvm::DebugCompressionType::Z)
+              .Case("zlib-gnu", llvm::DebugCompressionType::GNU)
+              .Default(llvm::DebugCompressionType::None);
+    }
+  }
+
+  Opts.RelaxELFRelocations = Args.hasArg(OPT_mrelax_relocations);
+  Opts.DwarfVersion = getLastArgIntValue(Args, OPT_dwarf_version_EQ, 2, Diags);
+  Opts.DwarfDebugFlags =
+      std::string(Args.getLastArgValue(OPT_dwarf_debug_flags));
+  Opts.DwarfDebugProducer =
+      std::string(Args.getLastArgValue(OPT_dwarf_debug_producer));
+  Opts.DebugCompilationDir =
+      std::string(Args.getLastArgValue(OPT_fdebug_compilation_dir));
+  Opts.MainFileName = std::string(Args.getLastArgValue(OPT_main_file_name));
+
+  for (const auto &Arg : Args.getAllArgValues(OPT_fdebug_prefix_map_EQ)) {
+    auto Split = StringRef(Arg).split('=');
+    Opts.DebugPrefixMap.insert(
+        {std::string(Split.first), std::string(Split.second)});
+  }
+
+  // Frontend Options
+  if (Args.hasArg(OPT_INPUT)) {
+    bool First = true;
+    for (const Arg *A : Args.filtered(OPT_INPUT)) {
+      if (First) {
+        Opts.InputFile = A->getValue();
+        First = false;
+      } else {
+        Diags.Report(diag::err_drv_unknown_argument) << A->getAsString(Args);
+        Success = false;
+      }
+    }
+  }
+  Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
+  Opts.OutputPath = std::string(Args.getLastArgValue(OPT_o));
+  Opts.SplitDwarfOutput =
+      std::string(Args.getLastArgValue(OPT_split_dwarf_output));
+  if (Arg *A = Args.getLastArg(OPT_filetype)) {
+    StringRef Name = A->getValue();
+    unsigned OutputType = StringSwitch<unsigned>(Name)
+      .Case("asm", FT_Asm)
+      .Case("null", FT_Null)
+      .Case("obj", FT_Obj)
+      .Default(~0U);
+    if (OutputType == ~0U) {
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Name;
+      Success = false;
+    } else
+      Opts.OutputType = FileType(OutputType);
+  }
+  Opts.ShowHelp = Args.hasArg(OPT_help);
+  Opts.ShowVersion = Args.hasArg(OPT_version);
+
+  // Transliterate Options
+  Opts.OutputAsmVariant =
+      getLastArgIntValue(Args, OPT_output_asm_variant, 0, Diags);
+  Opts.ShowEncoding = Args.hasArg(OPT_show_encoding);
+  Opts.ShowInst = Args.hasArg(OPT_show_inst);
+
+  // Assemble Options
+  Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
+  Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
+  Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
+  Opts.NoWarn = Args.hasArg(OPT_massembler_no_warn);
+  Opts.RelocationModel =
+      std::string(Args.getLastArgValue(OPT_mrelocation_model, "pic"));
+  Opts.TargetABI = std::string(Args.getLastArgValue(OPT_target_abi));
+  Opts.IncrementalLinkerCompatible =
+      Args.hasArg(OPT_mincremental_linker_compatible);
+  Opts.SymbolDefs = Args.getAllArgValues(OPT_defsym);
+
+  // EmbedBitcode Option. If -fembed-bitcode is enabled, set the flag.
+  // EmbedBitcode behaves the same for all embed options for assembly files.
+  if (auto *A = Args.getLastArg(OPT_fembed_bitcode_EQ)) {
+    Opts.EmbedBitcode = llvm::StringSwitch<unsigned>(A->getValue())
+                            .Case("all", 1)
+                            .Case("bitcode", 1)
+                            .Case("marker", 1)
+                            .Default(0);
+  }
+
+  return Success;
+}
+
+static std::unique_ptr<raw_fd_ostream>
+getOutputStream(StringRef Path, DiagnosticsEngine &Diags, bool Binary) {
+  // Make sure that the Out file gets unlinked from the disk if we get a
+  // SIGINT.
+  if (Path != "-")
+    sys::RemoveFileOnSignal(Path);
+
+  std::error_code EC;
+  auto Out = std::make_unique<raw_fd_ostream>(
+      Path, EC, (Binary ? sys::fs::OF_None : sys::fs::OF_Text));
+  if (EC) {
+    Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
+    return nullptr;
+  }
+
+  return Out;
+}
+
+bool ExecuteAssembler(AssemblerInvocation &Opts, DiagnosticsEngine &Diags) {
+  // Get the target specific parser.
+  std::string Error;
+  const Target *TheTarget = TargetRegistry::lookupTarget(Opts.Triple, Error);
+  if (!TheTarget)
+    return Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
+
+  ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
+      MemoryBuffer::getFileOrSTDIN(Opts.InputFile);
+
+  if (std::error_code EC = Buffer.getError()) {
+    Error = EC.message();
+    return Diags.Report(diag::err_fe_error_reading) << Opts.InputFile;
+  }
+
+  SourceMgr SrcMgr;
+
+  // Tell SrcMgr about this buffer, which is what the parser will pick up.
+  unsigned BufferIndex = SrcMgr.AddNewSourceBuffer(std::move(*Buffer), SMLoc());
+
+  // Record the location of the include directories so that the lexer can find
+  // it later.
+  SrcMgr.setIncludeDirs(Opts.IncludePaths);
+
+  std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
+  assert(MRI && "Unable to create target register info!");
+
+  MCTargetOptions MCOptions;
+  std::unique_ptr<MCAsmInfo> MAI(
+      TheTarget->createMCAsmInfo(*MRI, Opts.Triple, MCOptions));
+  assert(MAI && "Unable to create target asm info!");
+
+  // Ensure MCAsmInfo initialization occurs before any use, otherwise sections
+  // may be created with a combination of default and explicit settings.
+  MAI->setCompressDebugSections(Opts.CompressDebugSections);
+
+  MAI->setRelaxELFRelocations(Opts.RelaxELFRelocations);
+
+  bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
+  if (Opts.OutputPath.empty())
+    Opts.OutputPath = "-";
+  std::unique_ptr<raw_fd_ostream> FDOS =
+      getOutputStream(Opts.OutputPath, Diags, IsBinary);
+  if (!FDOS)
+    return true;
+  std::unique_ptr<raw_fd_ostream> DwoOS;
+  if (!Opts.SplitDwarfOutput.empty())
+    DwoOS = getOutputStream(Opts.SplitDwarfOutput, Diags, IsBinary);
+
+  // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
+  // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
+  std::unique_ptr<MCObjectFileInfo> MOFI(new MCObjectFileInfo());
+
+  MCContext Ctx(MAI.get(), MRI.get(), MOFI.get(), &SrcMgr, &MCOptions);
+
+  bool PIC = false;
+  if (Opts.RelocationModel == "static") {
+    PIC = false;
+  } else if (Opts.RelocationModel == "pic") {
+    PIC = true;
+  } else {
+    assert(Opts.RelocationModel == "dynamic-no-pic" &&
+           "Invalid PIC model!");
+    PIC = false;
+  }
+
+  MOFI->InitMCObjectFileInfo(Triple(Opts.Triple), PIC, Ctx);
+  if (Opts.SaveTemporaryLabels)
+    Ctx.setAllowTemporaryLabels(false);
+  if (Opts.GenDwarfForAssembly)
+    Ctx.setGenDwarfForAssembly(true);
+  if (!Opts.DwarfDebugFlags.empty())
+    Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
+  if (!Opts.DwarfDebugProducer.empty())
+    Ctx.setDwarfDebugProducer(StringRef(Opts.DwarfDebugProducer));
+  if (!Opts.DebugCompilationDir.empty())
+    Ctx.setCompilationDir(Opts.DebugCompilationDir);
+  else {
+    // If no compilation dir is set, try to use the current directory.
+    SmallString<128> CWD;
+    if (!sys::fs::current_path(CWD))
+      Ctx.setCompilationDir(CWD);
+  }
+  if (!Opts.DebugPrefixMap.empty())
+    for (const auto &KV : Opts.DebugPrefixMap)
+      Ctx.addDebugPrefixMapEntry(KV.first, KV.second);
+  if (!Opts.MainFileName.empty())
+    Ctx.setMainFileName(StringRef(Opts.MainFileName));
+  Ctx.setDwarfVersion(Opts.DwarfVersion);
+  if (Opts.GenDwarfForAssembly)
+    Ctx.setGenDwarfRootFile(Opts.InputFile,
+                            SrcMgr.getMemoryBuffer(BufferIndex)->getBuffer());
+
+  // Build up the feature string from the target feature list.
+  std::string FS = llvm::join(Opts.Features, ",");
+
+  std::unique_ptr<MCStreamer> Str;
+
+  std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
+  std::unique_ptr<MCSubtargetInfo> STI(
+      TheTarget->createMCSubtargetInfo(Opts.Triple, Opts.CPU, FS));
+
+  raw_pwrite_stream *Out = FDOS.get();
+  std::unique_ptr<buffer_ostream> BOS;
+
+  MCOptions.MCNoWarn = Opts.NoWarn;
+  MCOptions.MCFatalWarnings = Opts.FatalWarnings;
+  MCOptions.ABIName = Opts.TargetABI;
+
+  // FIXME: There is a bit of code duplication with addPassesToEmitFile.
+  if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
+    MCInstPrinter *IP = TheTarget->createMCInstPrinter(
+        llvm::Triple(Opts.Triple), Opts.OutputAsmVariant, *MAI, *MCII, *MRI);
+
+    std::unique_ptr<MCCodeEmitter> CE;
+    if (Opts.ShowEncoding)
+      CE.reset(TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
+    std::unique_ptr<MCAsmBackend> MAB(
+        TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
+
+    auto FOut = std::make_unique<formatted_raw_ostream>(*Out);
+    Str.reset(TheTarget->createAsmStreamer(
+        Ctx, std::move(FOut), /*asmverbose*/ true,
+        /*useDwarfDirectory*/ true, IP, std::move(CE), std::move(MAB),
+        Opts.ShowInst));
+  } else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
+    Str.reset(createNullStreamer(Ctx));
+  } else {
+    assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
+           "Invalid file type!");
+    if (!FDOS->supportsSeeking()) {
+      BOS = std::make_unique<buffer_ostream>(*FDOS);
+      Out = BOS.get();
+    }
+
+    std::unique_ptr<MCCodeEmitter> CE(
+        TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
+    std::unique_ptr<MCAsmBackend> MAB(
+        TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
+    std::unique_ptr<MCObjectWriter> OW =
+        DwoOS ? MAB->createDwoObjectWriter(*Out, *DwoOS)
+              : MAB->createObjectWriter(*Out);
+
+    Triple T(Opts.Triple);
+    Str.reset(TheTarget->createMCObjectStreamer(
+        T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI,
+        Opts.RelaxAll, Opts.IncrementalLinkerCompatible,
+        /*DWARFMustBeAtTheEnd*/ true));
+    Str.get()->InitSections(Opts.NoExecStack);
+  }
+
+  // When -fembed-bitcode is passed to clang_as, a 1-byte marker
+  // is emitted in __LLVM,__asm section if the object file is MachO format.
+  if (Opts.EmbedBitcode && Ctx.getObjectFileInfo()->getObjectFileType() ==
+                               MCObjectFileInfo::IsMachO) {
+    MCSection *AsmLabel = Ctx.getMachOSection(
+        "__LLVM", "__asm", MachO::S_REGULAR, 4, SectionKind::getReadOnly());
+    Str.get()->SwitchSection(AsmLabel);
+    Str.get()->emitZeros(1);
+  }
+
+  // Assembly to object compilation should leverage assembly info.
+  Str->setUseAssemblerInfoForParsing(true);
+
+  bool Failed = false;
+
+  std::unique_ptr<MCAsmParser> Parser(
+      createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI));
+
+  // FIXME: init MCTargetOptions from sanitizer flags here.
+  std::unique_ptr<MCTargetAsmParser> TAP(
+      TheTarget->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
+  if (!TAP)
+    Failed = Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
+
+  // Set values for symbols, if any.
+  for (auto &S : Opts.SymbolDefs) {
+    auto Pair = StringRef(S).split('=');
+    auto Sym = Pair.first;
+    auto Val = Pair.second;
+    int64_t Value;
+    // We have already error checked this in the driver.
+    Val.getAsInteger(0, Value);
+    Ctx.setSymbolValue(Parser->getStreamer(), Sym, Value);
+  }
+
+  if (!Failed) {
+    Parser->setTargetParser(*TAP.get());
+    Failed = Parser->Run(Opts.NoInitialTextSection);
+  }
+
+  // Close Streamer first.
+  // It might have a reference to the output stream.
+  Str.reset();
+  // Close the output stream early.
+  BOS.reset();
+  FDOS.reset();
+
+  // Delete output file if there were errors.
+  if (Failed) {
+    if (Opts.OutputPath != "-")
+      sys::fs::remove(Opts.OutputPath);
+    if (!Opts.SplitDwarfOutput.empty() && Opts.SplitDwarfOutput != "-")
+      sys::fs::remove(Opts.SplitDwarfOutput);
+  }
+
+  return Failed;
+}
+
+static void LLVMErrorHandler(void *UserData, const std::string &Message,
+                             bool GenCrashDiag) {
+  DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
+
+  Diags.Report(diag::err_fe_error_backend) << Message;
+
+  // We cannot recover from llvm errors.
+  sys::Process::Exit(1);
+}
+
+int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
+  // Initialize targets and assembly printers/parsers.
+  InitializeAllTargetInfos();
+  InitializeAllTargetMCs();
+  InitializeAllAsmParsers();
+
+  // Construct our diagnostic client.
+  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+  TextDiagnosticPrinter *DiagClient
+    = new TextDiagnosticPrinter(errs(), &*DiagOpts);
+  DiagClient->setPrefix("clang -cc1as");
+  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+  DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
+
+  // Set an error handler, so that any LLVM backend diagnostics go through our
+  // error handler.
+  ScopedFatalErrorHandler FatalErrorHandler
+    (LLVMErrorHandler, static_cast<void*>(&Diags));
+
+  // Parse the arguments.
+  AssemblerInvocation Asm;
+  if (!AssemblerInvocation::CreateFromArgs(Asm, Argv, Diags))
+    return 1;
+
+  if (Asm.ShowHelp) {
+    getDriverOptTable().PrintHelp(
+        llvm::outs(), "clang -cc1as [options] file...",
+        "Clang Integrated Assembler",
+        /*Include=*/driver::options::CC1AsOption, /*Exclude=*/0,
+        /*ShowAllAliases=*/false);
+    return 0;
+  }
+
+  // Honor -version.
+  //
+  // FIXME: Use a better -version message?
+  if (Asm.ShowVersion) {
+    llvm::cl::PrintVersionMessage();
+    return 0;
+  }
+
+  // Honor -mllvm.
+  //
+  // FIXME: Remove this, one day.
+  if (!Asm.LLVMArgs.empty()) {
+    unsigned NumArgs = Asm.LLVMArgs.size();
+    auto Args = std::make_unique<const char*[]>(NumArgs + 2);
+    Args[0] = "clang (LLVM option parsing)";
+    for (unsigned i = 0; i != NumArgs; ++i)
+      Args[i + 1] = Asm.LLVMArgs[i].c_str();
+    Args[NumArgs + 1] = nullptr;
+    llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args.get());
+  }
+
+  // Execute the invocation, unless there were parsing errors.
+  bool Failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
+
+  // If any timers were active but haven't been destroyed yet, print their
+  // results now.
+  TimerGroup::printAll(errs());
+  TimerGroup::clearAll();
+
+  return !!Failed;
+}

builder/cc1as.h

@@ -0,0 +1,120 @@
+//===-- cc1as.h - Clang Assembler  ----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the entry point to the clang -cc1as functionality, which implements
+// the direct interface to the LLVM MC based assembler.
+//
+//===----------------------------------------------------------------------===//
+
+/// Helper class for representing a single invocation of the assembler.
+struct AssemblerInvocation {
+  /// @name Target Options
+  /// @{
+
+  /// The name of the target triple to assemble for.
+  std::string Triple;
+
+  /// If given, the name of the target CPU to determine which instructions
+  /// are legal.
+  std::string CPU;
+
+  /// The list of target specific features to enable or disable -- this should
+  /// be a list of strings starting with '+' or '-'.
+  std::vector<std::string> Features;
+
+  /// The list of symbol definitions.
+  std::vector<std::string> SymbolDefs;
+
+  /// @}
+  /// @name Language Options
+  /// @{
+
+  std::vector<std::string> IncludePaths;
+  unsigned NoInitialTextSection : 1;
+  unsigned SaveTemporaryLabels : 1;
+  unsigned GenDwarfForAssembly : 1;
+  unsigned RelaxELFRelocations : 1;
+  unsigned DwarfVersion;
+  std::string DwarfDebugFlags;
+  std::string DwarfDebugProducer;
+  std::string DebugCompilationDir;
+  std::map<const std::string, const std::string> DebugPrefixMap;
+  llvm::DebugCompressionType CompressDebugSections =
+      llvm::DebugCompressionType::None;
+  std::string MainFileName;
+  std::string SplitDwarfOutput;
+
+  /// @}
+  /// @name Frontend Options
+  /// @{
+
+  std::string InputFile;
+  std::vector<std::string> LLVMArgs;
+  std::string OutputPath;
+  enum FileType {
+    FT_Asm,  ///< Assembly (.s) output, transliterate mode.
+    FT_Null, ///< No output, for timing purposes.
+    FT_Obj   ///< Object file output.
+  };
+  FileType OutputType;
+  unsigned ShowHelp : 1;
+  unsigned ShowVersion : 1;
+
+  /// @}
+  /// @name Transliterate Options
+  /// @{
+
+  unsigned OutputAsmVariant;
+  unsigned ShowEncoding : 1;
+  unsigned ShowInst : 1;
+
+  /// @}
+  /// @name Assembler Options
+  /// @{
+
+  unsigned RelaxAll : 1;
+  unsigned NoExecStack : 1;
+  unsigned FatalWarnings : 1;
+  unsigned NoWarn : 1;
+  unsigned IncrementalLinkerCompatible : 1;
+  unsigned EmbedBitcode : 1;
+
+  /// The name of the relocation model to use.
+  std::string RelocationModel;
+
+  /// The ABI targeted by the backend. Specified using -target-abi. Empty
+  /// otherwise.
+  std::string TargetABI;
+
+  /// @}
+
+public:
+  AssemblerInvocation() {
+    Triple = "";
+    NoInitialTextSection = 0;
+    InputFile = "-";
+    OutputPath = "-";
+    OutputType = FT_Asm;
+    OutputAsmVariant = 0;
+    ShowInst = 0;
+    ShowEncoding = 0;
+    RelaxAll = 0;
+    NoExecStack = 0;
+    FatalWarnings = 0;
+    NoWarn = 0;
+    IncrementalLinkerCompatible = 0;
+    DwarfVersion = 0;
+    EmbedBitcode = 0;
+  }
+
+  static bool CreateFromArgs(AssemblerInvocation &Res,
+                             ArrayRef<const char *> Argv,
+                             DiagnosticsEngine &Diags);
+};
+
+bool ExecuteAssembler(AssemblerInvocation &Opts, DiagnosticsEngine &Diags);

builder/clang.cpp

@@ -0,0 +1,98 @@
+// +build byollvm
+
+#include <clang/Basic/DiagnosticOptions.h>
+#include <clang/CodeGen/CodeGenAction.h>
+#include <clang/Driver/Compilation.h>
+#include <clang/Driver/Driver.h>
+#include <clang/Frontend/CompilerInstance.h>
+#include <clang/Frontend/CompilerInvocation.h>
+#include <clang/Frontend/FrontendDiagnostic.h>
+#include <clang/Frontend/TextDiagnosticPrinter.h>
+#include <clang/FrontendTool/Utils.h>
+#include <llvm/ADT/IntrusiveRefCntPtr.h>
+#include <llvm/Option/Option.h>
+#include <llvm/Support/Host.h>
+
+using namespace llvm;
+using namespace clang;
+
+#include "cc1as.h"
+
+// This file provides C wrappers for the builtin tools cc1 and cc1as
+// provided by Clang, and calls them as the driver would call them.
+
+extern "C" {
+
+bool tinygo_clang_driver(int argc, char **argv) {
+	std::vector<const char*> args(argv, argv + argc);
+
+	// The compiler invocation needs a DiagnosticsEngine so it can report problems
+	llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> DiagOpts = new clang::DiagnosticOptions();
+	clang::TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), &*DiagOpts);
+	clang::DiagnosticsEngine Diags(llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs>(new clang::DiagnosticIDs()), &*DiagOpts, &DiagnosticPrinter, false);
+
+	// Create the clang driver
+	clang::driver::Driver TheDriver(args[0], llvm::sys::getDefaultTargetTriple(), Diags);
+
+	// Create the set of actions to perform
+	std::unique_ptr<clang::driver::Compilation> C(TheDriver.BuildCompilation(args));
+	if (!C) {
+		return false;
+	}
+	const clang::driver::JobList &Jobs = C->getJobs();
+
+	// There may be more than one job, for example for .S files
+	// (preprocessor + assembler).
+	for (auto Cmd : Jobs) {
+		// Select the tool: cc1 or cc1as.
+		const llvm::opt::ArgStringList &CCArgs = Cmd.getArguments();
+
+		if (strcmp(*CCArgs.data(), "-cc1") == 0) {
+			// This is the C frontend.
+			// Initialize a compiler invocation object from the clang (-cc1) arguments.
+			std::unique_ptr<clang::CompilerInstance> Clang(new clang::CompilerInstance());
+			bool success = clang::CompilerInvocation::CreateFromArgs(
+					Clang->getInvocation(),
+					CCArgs,
+					Diags);
+			if (!success) {
+				return false;
+			}
+
+			// Create the actual diagnostics engine.
+			Clang->createDiagnostics();
+			if (!Clang->hasDiagnostics()) {
+				return false;
+			}
+
+			// Execute the frontend actions.
+			success = ExecuteCompilerInvocation(Clang.get());
+			if (!success) {
+				return false;
+			}
+
+		} else if (strcmp(*CCArgs.data(), "-cc1as") == 0) {
+			// This is the assembler frontend. Parse the arguments.
+			AssemblerInvocation Asm;
+			ArrayRef<const char *> Argv = llvm::ArrayRef<const char*>(CCArgs);
+			if (!AssemblerInvocation::CreateFromArgs(Asm, Argv.slice(1), Diags))
+				return false;
+
+			// Execute the invocation, unless there were parsing errors.
+			bool failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
+			if (failed) {
+				return false;
+			}
+
+		} else {
+			// Unknown tool, print the tool and exit.
+			fprintf(stderr, "unknown tool: %s\n", *CCArgs.data());
+			return false;
+		}
+	}
+
+	// Commands executed successfully.
+	return true;
+}
+
+} // extern "C"

builder/commands.go

@@ -0,0 +1,65 @@
+package builder
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"tinygo.org/x/go-llvm"
+)
+
+// Commands lists command alternatives for various operating systems. These
+// commands may have a slightly different name across operating systems and
+// distributions or may not even exist in $PATH, in which case absolute paths
+// may be used.
+var commands = map[string][]string{}
+
+func init() {
+	llvmMajor := strings.Split(llvm.Version, ".")[0]
+	commands["clang"] = []string{"clang-" + llvmMajor}
+	commands["ld.lld"] = []string{"ld.lld-" + llvmMajor, "ld.lld"}
+	commands["wasm-ld"] = []string{"wasm-ld-" + llvmMajor, "wasm-ld"}
+	// Add the path to a Homebrew-installed LLVM for ease of use (no need to
+	// manually set $PATH).
+	if runtime.GOOS == "darwin" {
+		prefix := "/usr/local/opt/llvm@" + llvmMajor + "/bin/"
+		commands["clang"] = append(commands["clang"], prefix+"clang-"+llvmMajor)
+		commands["ld.lld"] = append(commands["ld.lld"], prefix+"ld.lld")
+		commands["wasm-ld"] = append(commands["wasm-ld"], prefix+"wasm-ld")
+	}
+	// Add the path for when LLVM was installed with the installer from
+	// llvm.org, which by default doesn't add LLVM to the $PATH environment
+	// variable.
+	if runtime.GOOS == "windows" {
+		commands["clang"] = append(commands["clang"], "clang", "C:\\Program Files\\LLVM\\bin\\clang.exe")
+		commands["ld.lld"] = append(commands["ld.lld"], "lld", "C:\\Program Files\\LLVM\\bin\\lld.exe")
+		commands["wasm-ld"] = append(commands["wasm-ld"], "C:\\Program Files\\LLVM\\bin\\wasm-ld.exe")
+	}
+	// Add the path to LLVM installed from ports.
+	if runtime.GOOS == "freebsd" {
+		prefix := "/usr/local/llvm" + llvmMajor + "/bin/"
+		commands["clang"] = append(commands["clang"], prefix+"clang-"+llvmMajor)
+		commands["ld.lld"] = append(commands["ld.lld"], prefix+"ld.lld")
+		commands["wasm-ld"] = append(commands["wasm-ld"], prefix+"wasm-ld")
+	}
+}
+
+func execCommand(cmdNames []string, args ...string) error {
+	for _, cmdName := range cmdNames {
+		cmd := exec.Command(cmdName, args...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err := cmd.Run()
+		if err != nil {
+			if err, ok := err.(*exec.Error); ok && (err.Err == exec.ErrNotFound || err.Err.Error() == "file does not exist") {
+				// this command was not found, try the next
+				continue
+			}
+			return err
+		}
+		return nil
+	}
+	return errors.New("none of these commands were found in your $PATH: " + strings.Join(cmdNames, " "))
+}

builder/config.go

@@ -0,0 +1,39 @@
+package builder
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// NewConfig builds a new Config object from a set of compiler options. It also
+// loads some information from the environment while doing that. For example, it
+// uses the currently active GOPATH (from the goenv package) to determine the Go
+// version to use.
+func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
+	spec, err := compileopts.LoadTarget(options.Target)
+	if err != nil {
+		return nil, err
+	}
+	goroot := goenv.Get("GOROOT")
+	if goroot == "" {
+		return nil, errors.New("cannot locate $GOROOT, please set it manually")
+	}
+	major, minor, err := goenv.GetGorootVersion(goroot)
+	if err != nil {
+		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
+	}
+	if major != 1 || minor < 13 || minor > 16 {
+		return nil, fmt.Errorf("requires go version 1.13 through 1.16, got go%d.%d", major, minor)
+	}
+	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
+	return &compileopts.Config{
+		Options:        options,
+		Target:         spec,
+		GoMinorVersion: minor,
+		ClangHeaders:   clangHeaderPath,
+		TestConfig:     options.TestConfig,
+	}, nil
+}

builder/env.go

@@ -0,0 +1,89 @@
+package builder
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"tinygo.org/x/go-llvm"
+)
+
+// getClangHeaderPath returns the path to the built-in Clang headers. It tries
+// multiple locations, which should make it find the directory when installed in
+// various ways.
+func getClangHeaderPath(TINYGOROOT string) string {
+	// Check whether we're running from the source directory.
+	path := filepath.Join(TINYGOROOT, "llvm-project", "clang", "lib", "Headers")
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		return path
+	}
+
+	// Check whether we're running from the installation directory.
+	path = filepath.Join(TINYGOROOT, "lib", "clang", "include")
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		return path
+	}
+
+	// It looks like we are built with a system-installed LLVM. Do a last
+	// attempt: try to use Clang headers relative to the clang binary.
+	llvmMajor := strings.Split(llvm.Version, ".")[0]
+	for _, cmdName := range commands["clang"] {
+		binpath, err := exec.LookPath(cmdName)
+		if err == nil {
+			// This should be the command that will also be used by
+			// execCommand. To avoid inconsistencies, make sure we use the
+			// headers relative to this command.
+			binpath, err = filepath.EvalSymlinks(binpath)
+			if err != nil {
+				// Unexpected.
+				return ""
+			}
+			// Example executable:
+			//     /usr/lib/llvm-9/bin/clang
+			// Example include path:
+			//     /usr/lib/llvm-9/lib64/clang/9.0.1/include/
+			llvmRoot := filepath.Dir(filepath.Dir(binpath))
+			clangVersionRoot := filepath.Join(llvmRoot, "lib64", "clang")
+			dirs64, err64 := ioutil.ReadDir(clangVersionRoot)
+			// Example include path:
+			//     /usr/lib/llvm-9/lib/clang/9.0.1/include/
+			clangVersionRoot = filepath.Join(llvmRoot, "lib", "clang")
+			dirs32, err32 := ioutil.ReadDir(clangVersionRoot)
+			if err64 != nil && err32 != nil {
+				// Unexpected.
+				continue
+			}
+			dirnames := make([]string, len(dirs64)+len(dirs32))
+			dirCount := 0
+			for _, d := range dirs32 {
+				name := d.Name()
+				if name == llvmMajor || strings.HasPrefix(name, llvmMajor+".") {
+					dirnames[dirCount] = filepath.Join(llvmRoot, "lib", "clang", name)
+					dirCount++
+				}
+			}
+			for _, d := range dirs64 {
+				name := d.Name()
+				if name == llvmMajor || strings.HasPrefix(name, llvmMajor+".") {
+					dirnames[dirCount] = filepath.Join(llvmRoot, "lib64", "clang", name)
+					dirCount++
+				}
+			}
+			sort.Strings(dirnames)
+			// Check for the highest version first.
+			for i := dirCount - 1; i >= 0; i-- {
+				path := filepath.Join(dirnames[i], "include")
+				_, err := os.Stat(filepath.Join(path, "stdint.h"))
+				if err == nil {
+					return path
+				}
+			}
+		}
+	}
+
+	// Could not find it.
+	return ""
+}

builder/error.go

@@ -0,0 +1,39 @@
+package builder
+
+// MultiError is a list of multiple errors (actually: diagnostics) returned
+// during LLVM IR generation.
+type MultiError struct {
+	Errs []error
+}
+
+func (e *MultiError) Error() string {
+	// Return the first error, to conform to the error interface. Clients should
+	// really do a type-assertion on *MultiError.
+	return e.Errs[0].Error()
+}
+
+// newMultiError returns a *MultiError if there is more than one error, or
+// returns that error directly when there is only one. Passing an empty slice
+// will lead to a panic.
+func newMultiError(errs []error) error {
+	switch len(errs) {
+	case 0:
+		panic("attempted to create empty MultiError")
+	case 1:
+		return errs[0]
+	default:
+		return &MultiError{errs}
+	}
+}
+
+// commandError is an error type to wrap os/exec.Command errors. This provides
+// some more information regarding what went wrong while running a command.
+type commandError struct {
+	Msg  string
+	File string
+	Err  error
+}
+
+func (e *commandError) Error() string {
+	return e.Msg + " " + e.File + ": " + e.Err.Error()
+}

builder/esp.go

@@ -0,0 +1,153 @@
+package builder
+
+// This file implements support for writing ESP image files. These image files
+// are read by the ROM bootloader so have to be in a particular format.
+//
+// In the future, it may be necessary to implement support for other image
+// formats, such as the ESP8266 image formats (again, used by the ROM bootloader
+// to load the firmware).
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"debug/elf"
+	"encoding/binary"
+	"fmt"
+	"io/ioutil"
+	"sort"
+)
+
+type espImageSegment struct {
+	addr uint32
+	data []byte
+}
+
+// makeESPFirmare converts an input ELF file to an image file for an ESP32 or
+// ESP8266 chip. This is a special purpose image format just for the ESP chip
+// family, and is parsed by the on-chip mask ROM bootloader.
+//
+// The following documentation has been used:
+// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
+// https://github.com/espressif/esp-idf/blob/8fbb63c2a701c22ccf4ce249f43aded73e134a34/components/bootloader_support/include/esp_image_format.h#L58
+// https://github.com/espressif/esptool/blob/master/esptool.py
+func makeESPFirmareImage(infile, outfile, format string) error {
+	inf, err := elf.Open(infile)
+	if err != nil {
+		return err
+	}
+	defer inf.Close()
+
+	// Load all segments to be written to the image. These are actually ELF
+	// sections, not true ELF segments (similar to how esptool does it).
+	var segments []*espImageSegment
+	for _, section := range inf.Sections {
+		if section.Type != elf.SHT_PROGBITS || section.Size == 0 || section.Flags&elf.SHF_ALLOC == 0 {
+			continue
+		}
+		data, err := section.Data()
+		if err != nil {
+			return fmt.Errorf("failed to read section data: %w", err)
+		}
+		for len(data)%4 != 0 {
+			// Align segment to 4 bytes.
+			data = append(data, 0)
+		}
+		if uint64(uint32(section.Addr)) != section.Addr {
+			return fmt.Errorf("section address too big: 0x%x", section.Addr)
+		}
+		segments = append(segments, &espImageSegment{
+			addr: uint32(section.Addr),
+			data: data,
+		})
+	}
+
+	// Sort the segments by address. This is what esptool does too.
+	sort.SliceStable(segments, func(i, j int) bool { return segments[i].addr < segments[j].addr })
+
+	// Calculate checksum over the segment data. This is used in the image
+	// footer.
+	checksum := uint8(0xef)
+	for _, segment := range segments {
+		for _, b := range segment.data {
+			checksum ^= b
+		}
+	}
+
+	// Write first to an in-memory buffer, primarily so that we can easily
+	// calculate a hash over the entire image.
+	// An added benefit is that we don't need to check for errors all the time.
+	outf := &bytes.Buffer{}
+
+	// Image header.
+	switch format {
+	case "esp32":
+		// Header format:
+		// https://github.com/espressif/esp-idf/blob/8fbb63c2/components/bootloader_support/include/esp_image_format.h#L58
+		binary.Write(outf, binary.LittleEndian, struct {
+			magic          uint8
+			segment_count  uint8
+			spi_mode       uint8
+			spi_speed_size uint8
+			entry_addr     uint32
+			wp_pin         uint8
+			spi_pin_drv    [3]uint8
+			reserved       [11]uint8
+			hash_appended  bool
+		}{
+			magic:          0xE9,
+			segment_count:  byte(len(segments)),
+			spi_mode:       0, // irrelevant, replaced by esptool when flashing
+			spi_speed_size: 0, // spi_speed, spi_size: replaced by esptool when flashing
+			entry_addr:     uint32(inf.Entry),
+			wp_pin:         0xEE, // disable WP pin
+			hash_appended:  true, // add a SHA256 hash
+		})
+	case "esp8266":
+		// Header format:
+		// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
+		// Basically a truncated version of the ESP32 header.
+		binary.Write(outf, binary.LittleEndian, struct {
+			magic          uint8
+			segment_count  uint8
+			spi_mode       uint8
+			spi_speed_size uint8
+			entry_addr     uint32
+		}{
+			magic:          0xE9,
+			segment_count:  byte(len(segments)),
+			spi_mode:       0,    // irrelevant, replaced by esptool when flashing
+			spi_speed_size: 0x20, // spi_speed, spi_size: replaced by esptool when flashing
+			entry_addr:     uint32(inf.Entry),
+		})
+	default:
+		return fmt.Errorf("builder: unknown binary format %#v, expected esp32 or esp8266", format)
+	}
+
+	// Write all segments to the image.
+	// https://github.com/espressif/esptool/wiki/Firmware-Image-Format#segment
+	for _, segment := range segments {
+		binary.Write(outf, binary.LittleEndian, struct {
+			addr   uint32
+			length uint32
+		}{
+			addr:   segment.addr,
+			length: uint32(len(segment.data)),
+		})
+		outf.Write(segment.data)
+	}
+
+	// Footer, including checksum.
+	// The entire image size must be a multiple of 16, so pad the image to one
+	// byte less than that before writing the checksum.
+	outf.Write(make([]byte, 15-outf.Len()%16))
+	outf.WriteByte(checksum)
+
+	if format == "esp32" {
+		// SHA256 hash (to protect against image corruption, not for security).
+		hash := sha256.Sum256(outf.Bytes())
+		outf.Write(hash[:])
+	}
+
+	// Write the image to the output file.
+	return ioutil.WriteFile(outfile, outf.Bytes(), 0666)
+}

builder/jobs.go

@@ -0,0 +1,160 @@
+package builder
+
+// This file implements a job runner for the compiler, which runs jobs in
+// parallel while taking care of dependencies.
+
+import (
+	"fmt"
+	"runtime"
+	"time"
+)
+
+// Set to true to enable logging in the job runner. This may help to debug
+// concurrency or performance issues.
+const jobRunnerDebug = false
+
+type jobState uint8
+
+const (
+	jobStateQueued   jobState = iota // not yet running
+	jobStateRunning                  // running
+	jobStateFinished                 // finished running
+)
+
+// compileJob is a single compiler job, comparable to a single Makefile target.
+// It is used to orchestrate various compiler tasks that can be run in parallel
+// but that have dependencies and thus have limitations in how they can be run.
+type compileJob struct {
+	description  string // description, only used for logging
+	dependencies []*compileJob
+	run          func() error
+	state        jobState
+	err          error         // error if finished
+	duration     time.Duration // how long it took to run this job (only set after finishing)
+}
+
+// readyToRun returns whether this job is ready to run: it is itself not yet
+// started and all dependencies are finished.
+func (job *compileJob) readyToRun() bool {
+	if job.state != jobStateQueued {
+		// Already running or finished, so shouldn't be run again.
+		return false
+	}
+
+	// Check dependencies.
+	for _, dep := range job.dependencies {
+		if dep.state != jobStateFinished {
+			// A dependency is not finished, so this job has to wait until it
+			// is.
+			return false
+		}
+	}
+
+	// All conditions are satisfied.
+	return true
+}
+
+// runJobs runs all the jobs indicated in the jobs slice and returns the error
+// of the first job that fails to run.
+// It runs all jobs in the order of the slice, as long as all dependencies have
+// already run. Therefore, if some jobs are preferred to run before others, they
+// should be ordered as such in this slice.
+func runJobs(jobs []*compileJob) error {
+	// Create channels to communicate with the workers.
+	doneChan := make(chan *compileJob)
+	workerChan := make(chan *compileJob)
+	defer close(workerChan)
+
+	// Start a number of workers.
+	for i := 0; i < runtime.NumCPU(); i++ {
+		if jobRunnerDebug {
+			fmt.Println("## starting worker", i)
+		}
+		go jobWorker(workerChan, doneChan)
+	}
+
+	// Send each job in the jobs slice to a worker, taking care of job
+	// dependencies.
+	numRunningJobs := 0
+	var totalTime time.Duration
+	start := time.Now()
+	for {
+		// If there are free workers, try starting a new job (if one is
+		// available). If it succeeds, try again to fill the entire worker pool.
+		if numRunningJobs < runtime.NumCPU() {
+			jobToRun := nextJob(jobs)
+			if jobToRun != nil {
+				// Start job.
+				if jobRunnerDebug {
+					fmt.Println("## start:   ", jobToRun.description)
+				}
+				jobToRun.state = jobStateRunning
+				workerChan <- jobToRun
+				numRunningJobs++
+				continue
+			}
+		}
+
+		// When there are no jobs running, all jobs in the jobs slice must have
+		// been finished. Therefore, the work is done.
+		if numRunningJobs == 0 {
+			break
+		}
+
+		// Wait until a job is finished.
+		job := <-doneChan
+		job.state = jobStateFinished
+		numRunningJobs--
+		totalTime += job.duration
+		if jobRunnerDebug {
+			fmt.Println("## finished:", job.description, "(time "+job.duration.String()+")")
+		}
+		if job.err != nil {
+			// Wait for running jobs to finish.
+			for numRunningJobs != 0 {
+				<-doneChan
+				numRunningJobs--
+			}
+			// Return error of first failing job.
+			return job.err
+		}
+	}
+
+	// Some statistics, if debugging.
+	if jobRunnerDebug {
+		// Total duration of running all jobs.
+		duration := time.Since(start)
+		fmt.Println("## total:   ", duration)
+
+		// The individual time of each job combined. On a multicore system, this
+		// should be lower than the total above.
+		fmt.Println("## job sum: ", totalTime)
+	}
+
+	return nil
+}
+
+// nextJob returns the first ready-to-run job.
+// This is an implementation detail of runJobs.
+func nextJob(jobs []*compileJob) *compileJob {
+	for _, job := range jobs {
+		if job.readyToRun() {
+			return job
+		}
+	}
+	return nil
+}
+
+// jobWorker is the goroutine that runs received jobs.
+// This is an implementation detail of runJobs.
+func jobWorker(workerChan, doneChan chan *compileJob) {
+	for job := range workerChan {
+		start := time.Now()
+		err := job.run()
+		if err != nil {
+			job.err = err
+		}
+		job.duration = time.Since(start)
+		doneChan <- job
+	}
+}

builder/library.go

@@ -0,0 +1,150 @@
+package builder
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// Library is a container for information about a single C library, such as a
+// compiler runtime or libc.
+type Library struct {
+	// The library name, such as compiler-rt or picolibc.
+	name string
+
+	cflags func() []string
+
+	// The source directory, relative to TINYGOROOT.
+	sourceDir string
+
+	// The source files, relative to sourceDir.
+	sources func(target string) []string
+}
+
+// fullPath returns the full path to the source directory.
+func (l *Library) fullPath() string {
+	return filepath.Join(goenv.Get("TINYGOROOT"), l.sourceDir)
+}
+
+// sourcePaths returns a slice with the full paths to the source files.
+func (l *Library) sourcePaths(target string) []string {
+	sources := l.sources(target)
+	paths := make([]string, len(sources))
+	for i, name := range sources {
+		paths[i] = filepath.Join(l.fullPath(), name)
+	}
+	return paths
+}
+
+// Load the library archive, possibly generating and caching it if needed.
+// The resulting file is stored in the provided tmpdir, which is expected to be
+// removed after the Load call.
+func (l *Library) Load(target, tmpdir string) (path string, err error) {
+	path, job, err := l.load(target, "", tmpdir)
+	if err != nil {
+		return "", err
+	}
+	if job != nil {
+		jobs := append([]*compileJob{job}, job.dependencies...)
+		err = runJobs(jobs)
+	}
+	return path, err
+}
+
+// load returns a path to the library file for the given target, loading it from
+// cache if possible. It will return a non-zero compiler job if the library
+// wasn't cached, this job (and its dependencies) must be run before the library
+// path is valid.
+// The provided tmpdir will be used to store intermediary files and possibly the
+// output archive file, it is expected to be removed after use.
+func (l *Library) load(target, cpu, tmpdir string) (path string, job *compileJob, err error) {
+	// Try to load a precompiled library.
+	precompiledPath := filepath.Join(goenv.Get("TINYGOROOT"), "pkg", target, l.name+".a")
+	if _, err := os.Stat(precompiledPath); err == nil {
+		// Found a precompiled library for this OS/architecture. Return the path
+		// directly.
+		return precompiledPath, nil, nil
+	}
+
+	var outfile string
+	if cpu != "" {
+		outfile = l.name + "-" + target + "-" + cpu + ".a"
+	} else {
+		outfile = l.name + "-" + target + ".a"
+	}
+
+	// Try to fetch this library from the cache.
+	if path, err := cacheLoad(outfile, l.sourcePaths(target)); path != "" || err != nil {
+		// Cache hit.
+		return path, nil, err
+	}
+	// Cache miss, build it now.
+
+	remapDir := filepath.Join(os.TempDir(), "tinygo-"+l.name)
+	dir := filepath.Join(tmpdir, "build-lib-"+l.name)
+	err = os.Mkdir(dir, 0777)
+	if err != nil {
+		return "", nil, err
+	}
+
+	// Precalculate the flags to the compiler invocation.
+	// Note: -fdebug-prefix-map is necessary to make the output archive
+	// reproducible. Otherwise the temporary directory is stored in the archive
+	// itself, which varies each run.
+	args := append(l.cflags(), "-c", "-Oz", "-g", "-ffunction-sections", "-fdata-sections", "-Wno-macro-redefined", "--target="+target, "-fdebug-prefix-map="+dir+"="+remapDir)
+	if cpu != "" {
+		args = append(args, "-mcpu="+cpu)
+	}
+	if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
+		args = append(args, "-fshort-enums", "-fomit-frame-pointer", "-mfloat-abi=soft")
+	}
+	if strings.HasPrefix(target, "riscv32-") {
+		args = append(args, "-march=rv32imac", "-mabi=ilp32", "-fforce-enable-int128")
+	}
+	if strings.HasPrefix(target, "riscv64-") {
+		args = append(args, "-march=rv64gc", "-mabi=lp64")
+	}
+
+	// Create job to put all the object files in a single archive. This archive
+	// file is the (static) library file.
+	var objs []string
+	arpath := filepath.Join(dir, l.name+".a")
+	job = &compileJob{
+		description: "ar " + l.name + ".a",
+		run: func() error {
+			// Create an archive of all object files.
+			err := makeArchive(arpath, objs)
+			if err != nil {
+				return err
+			}
+			// Store this archive in the cache.
+			_, err = cacheStore(arpath, outfile, l.sourcePaths(target))
+			return err
+		},
+	}
+
+	// Create jobs to compile all sources. These jobs are depended upon by the
+	// archive job above, so must be run first.
+	for _, srcpath := range l.sourcePaths(target) {
+		srcpath := srcpath // avoid concurrency issues by redefining inside the loop
+		objpath := filepath.Join(dir, filepath.Base(srcpath)+".o")
+		objs = append(objs, objpath)
+		job.dependencies = append(job.dependencies, &compileJob{
+			description: "compile " + srcpath,
+			run: func() error {
+				var compileArgs []string
+				compileArgs = append(compileArgs, args...)
+				compileArgs = append(compileArgs, "-o", objpath, srcpath)
+				err := runCCompiler("clang", compileArgs...)
+				if err != nil {
+					return &commandError{"failed to build", srcpath, err}
+				}
+				return nil
+			},
+		})
+	}
+
+	return arpath, job, nil
+}

builder/lld.cpp

@@ -0,0 +1,19 @@
+// +build byollvm
+
+// This file provides C wrappers for liblld.
+
+#include <lld/Common/Driver.h>
+
+extern "C" {
+
+bool tinygo_link_elf(int argc, char **argv) {
+	std::vector<const char*> args(argv, argv + argc);
+	return lld::elf::link(args, false, llvm::outs(), llvm::errs());
+}
+
+bool tinygo_link_wasm(int argc, char **argv) {
+	std::vector<const char*> args(argv, argv + argc);
+	return lld::wasm::link(args, false, llvm::outs(), llvm::errs());
+}
+
+} // external "C"

builder/objcopy.go

@@ -0,0 +1,141 @@
+package builder
+
+import (
+	"debug/elf"
+	"io/ioutil"
+	"os"
+	"sort"
+
+	"github.com/marcinbor85/gohex"
+)
+
+// maxPadBytes is the maximum allowed bytes to be padded in a rom extraction
+// this value is currently defined by Nintendo Switch Page Alignment (4096 bytes)
+const maxPadBytes = 4095
+
+// objcopyError is an error returned by functions that act like objcopy.
+type objcopyError struct {
+	Op  string
+	Err error
+}
+
+func (e objcopyError) Error() string {
+	if e.Err == nil {
+		return e.Op
+	}
+	return e.Op + ": " + e.Err.Error()
+}
+
+type progSlice []*elf.Prog
+
+func (s progSlice) Len() int           { return len(s) }
+func (s progSlice) Less(i, j int) bool { return s[i].Paddr < s[j].Paddr }
+func (s progSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// extractROM extracts a firmware image and the first load address from the
+// given ELF file. It tries to emulate the behavior of objcopy.
+func extractROM(path string) (uint64, []byte, error) {
+	f, err := elf.Open(path)
+	if err != nil {
+		return 0, nil, objcopyError{"failed to open ELF file to extract text segment", err}
+	}
+	defer f.Close()
+
+	// The GNU objcopy command does the following for firmware extraction (from
+	// the man page):
+	// > When objcopy generates a raw binary file, it will essentially produce a
+	// > memory dump of the contents of the input object file. All symbols and
+	// > relocation information will be discarded. The memory dump will start at
+	// > the load address of the lowest section copied into the output file.
+
+	// Find the lowest section address.
+	startAddr := ^uint64(0)
+	for _, section := range f.Sections {
+		if section.Type != elf.SHT_PROGBITS || section.Flags&elf.SHF_ALLOC == 0 {
+			continue
+		}
+		if section.Addr < startAddr {
+			startAddr = section.Addr
+		}
+	}
+
+	progs := make(progSlice, 0, 2)
+	for _, prog := range f.Progs {
+		if prog.Type != elf.PT_LOAD || prog.Filesz == 0 || prog.Off == 0 {
+			continue
+		}
+		progs = append(progs, prog)
+	}
+	if len(progs) == 0 {
+		return 0, nil, objcopyError{"file does not contain ROM segments: " + path, nil}
+	}
+	sort.Sort(progs)
+
+	var rom []byte
+	for _, prog := range progs {
+		romEnd := progs[0].Paddr + uint64(len(rom))
+		if prog.Paddr > romEnd && prog.Paddr < romEnd+16 {
+			// Sometimes, the linker seems to insert a bit of padding between
+			// segments. Simply zero-fill these parts.
+			rom = append(rom, make([]byte, prog.Paddr-romEnd)...)
+		}
+		if prog.Paddr != progs[0].Paddr+uint64(len(rom)) {
+			diff := prog.Paddr - (progs[0].Paddr + uint64(len(rom)))
+			if diff > maxPadBytes {
+				return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
+			}
+			// Pad the difference
+			rom = append(rom, make([]byte, diff)...)
+		}
+		data, err := ioutil.ReadAll(prog.Open())
+		if err != nil {
+			return 0, nil, objcopyError{"failed to extract segment from ELF file: " + path, err}
+		}
+		rom = append(rom, data...)
+	}
+	if progs[0].Paddr < startAddr {
+		// The lowest memory address is before the first section. This means
+		// that there is some extra data loaded at the start of the image that
+		// should be discarded.
+		// Example: ELF files where .text doesn't start at address 0 because
+		// there is a bootloader at the start.
+		return startAddr, rom[startAddr-progs[0].Paddr:], nil
+	} else {
+		return progs[0].Paddr, rom, nil
+	}
+}
+
+// objcopy converts an ELF file to a different (simpler) output file format:
+// .bin or .hex. It extracts only the .text section.
+func objcopy(infile, outfile, binaryFormat string) error {
+	f, err := os.OpenFile(outfile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	// Read the .text segment.
+	addr, data, err := extractROM(infile)
+	if err != nil {
+		return err
+	}
+
+	// Write to the file, in the correct format.
+	switch binaryFormat {
+	case "hex":
+		// Intel hex file, includes the firmware start address.
+		mem := gohex.NewMemory()
+		err := mem.AddBinary(uint32(addr), data)
+		if err != nil {
+			return objcopyError{"failed to create .hex file", err}
+		}
+		return mem.DumpIntelHex(f, 16)
+	case "bin":
+		// The start address is not stored in raw firmware files (therefore you
+		// should use .hex files in most cases).
+		_, err := f.Write(data)
+		return err
+	default:
+		panic("unreachable")
+	}
+}

builder/picolibc.go

@@ -0,0 +1,127 @@
+package builder
+
+import (
+	"path/filepath"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// Picolibc is a C library for bare metal embedded devices. It was originally
+// based on newlib.
+var Picolibc = Library{
+	name: "picolibc",
+	cflags: func() []string {
+		picolibcDir := filepath.Join(goenv.Get("TINYGOROOT"), "lib/picolibc/newlib/libc")
+		return []string{"-Werror", "-Wall", "-std=gnu11", "-D_COMPILING_NEWLIB", "-nostdlibinc", "-Xclang", "-internal-isystem", "-Xclang", picolibcDir + "/include", "-I" + picolibcDir + "/tinystdio", "-I" + goenv.Get("TINYGOROOT") + "/lib/picolibc-include"}
+	},
+	sourceDir: "lib/picolibc/newlib/libc",
+	sources: func(target string) []string {
+		return picolibcSources
+	},
+}
+
+var picolibcSources = []string{
+	"string/bcmp.c",
+	"string/bcopy.c",
+	"string/bzero.c",
+	"string/explicit_bzero.c",
+	"string/ffsl.c",
+	"string/ffsll.c",
+	"string/fls.c",
+	"string/flsl.c",
+	"string/flsll.c",
+	"string/gnu_basename.c",
+	"string/index.c",
+	"string/memccpy.c",
+	"string/memchr.c",
+	"string/memcmp.c",
+	"string/memcpy.c",
+	"string/memmem.c",
+	"string/memmove.c",
+	"string/mempcpy.c",
+	"string/memrchr.c",
+	"string/memset.c",
+	"string/rawmemchr.c",
+	"string/rindex.c",
+	"string/stpcpy.c",
+	"string/stpncpy.c",
+	"string/strcasecmp.c",
+	"string/strcasecmp_l.c",
+	"string/strcasestr.c",
+	"string/strcat.c",
+	"string/strchr.c",
+	"string/strchrnul.c",
+	"string/strcmp.c",
+	"string/strcoll.c",
+	"string/strcoll_l.c",
+	"string/strcpy.c",
+	"string/strcspn.c",
+	"string/strdup.c",
+	"string/strerror.c",
+	"string/strerror_r.c",
+	"string/strlcat.c",
+	"string/strlcpy.c",
+	"string/strlen.c",
+	"string/strlwr.c",
+	"string/strncasecmp.c",
+	"string/strncasecmp_l.c",
+	"string/strncat.c",
+	"string/strncmp.c",
+	"string/strncpy.c",
+	"string/strndup.c",
+	"string/strnlen.c",
+	"string/strnstr.c",
+	"string/strpbrk.c",
+	"string/strrchr.c",
+	"string/strsep.c",
+	"string/strsignal.c",
+	"string/strspn.c",
+	"string/strstr.c",
+	"string/strtok.c",
+	"string/strtok_r.c",
+	"string/strupr.c",
+	"string/strverscmp.c",
+	"string/strxfrm.c",
+	"string/strxfrm_l.c",
+	"string/swab.c",
+	"string/timingsafe_bcmp.c",
+	"string/timingsafe_memcmp.c",
+	"string/u_strerr.c",
+	"string/wcpcpy.c",
+	"string/wcpncpy.c",
+	"string/wcscasecmp.c",
+	"string/wcscasecmp_l.c",
+	"string/wcscat.c",
+	"string/wcschr.c",
+	"string/wcscmp.c",
+	"string/wcscoll.c",
+	"string/wcscoll_l.c",
+	"string/wcscpy.c",
+	"string/wcscspn.c",
+	"string/wcsdup.c",
+	"string/wcslcat.c",
+	"string/wcslcpy.c",
+	"string/wcslen.c",
+	"string/wcsncasecmp.c",
+	"string/wcsncasecmp_l.c",
+	"string/wcsncat.c",
+	"string/wcsncmp.c",
+	"string/wcsncpy.c",
+	"string/wcsnlen.c",
+	"string/wcspbrk.c",
+	"string/wcsrchr.c",
+	"string/wcsspn.c",
+	"string/wcsstr.c",
+	"string/wcstok.c",
+	"string/wcswidth.c",
+	"string/wcsxfrm.c",
+	"string/wcsxfrm_l.c",
+	"string/wcwidth.c",
+	"string/wmemchr.c",
+	"string/wmemcmp.c",
+	"string/wmemcpy.c",
+	"string/wmemmove.c",
+	"string/wmempcpy.c",
+	"string/wmemset.c",
+	"string/xpg_strerror_r.c",
+}

builder/sizes.go

@@ -1,4 +1,4 @@
-package main
+package builder
 
 import (
 	"debug/elf"
@@ -6,18 +6,18 @@ import (
 	"strings"
 )
 
-// Statistics about code size in a program.
-type ProgramSize struct {
-	Packages map[string]*PackageSize
-	Sum      *PackageSize
+// programSize contains size statistics per package of a compiled program.
+type programSize struct {
+	Packages map[string]*packageSize
+	Sum      *packageSize
 	Code     uint64
 	Data     uint64
 	BSS      uint64
 }
 
-// Return the list of package names (ProgramSize.Packages) sorted
-// alphabetically.
-func (ps *ProgramSize) SortedPackageNames() []string {
+// sortedPackageNames returns the list of package names (ProgramSize.Packages)
+// sorted alphabetically.
+func (ps *programSize) sortedPackageNames() []string {
 	names := make([]string, 0, len(ps.Packages))
 	for name := range ps.Packages {
 		names = append(names, name)
@@ -26,8 +26,9 @@ func (ps *ProgramSize) SortedPackageNames() []string {
 	return names
 }
 
-// The size of a package, calculated from the linked object file.
-type PackageSize struct {
+// packageSize contains the size of a package, calculated from the linked object
+// file.
+type packageSize struct {
 	Code   uint64
 	ROData uint64
 	Data   uint64
@@ -35,12 +36,12 @@ type PackageSize struct {
 }
 
 // Flash usage in regular microcontrollers.
-func (ps *PackageSize) Flash() uint64 {
+func (ps *packageSize) Flash() uint64 {
 	return ps.Code + ps.ROData + ps.Data
 }
 
 // Static RAM usage in regular microcontrollers.
-func (ps *PackageSize) RAM() uint64 {
+func (ps *packageSize) RAM() uint64 {
 	return ps.Data + ps.BSS
 }
 
@@ -64,8 +65,9 @@ func (l symbolList) Swap(i, j int) {
 	l[i], l[j] = l[j], l[i]
 }
 
-// Calculate program/data size breakdown of each package for a given ELF file.
-func Sizes(path string) (*ProgramSize, error) {
+// loadProgramSize calculate a program/data size breakdown of each package for a
+// given ELF file.
+func loadProgramSize(path string) (*programSize, error) {
 	file, err := elf.Open(path)
 	if err != nil {
 		return nil, err
@@ -82,7 +84,18 @@ func Sizes(path string) (*ProgramSize, error) {
 		if section.Type != elf.SHT_PROGBITS && section.Type != elf.SHT_NOBITS {
 			continue
 		}
-		if section.Type == elf.SHT_NOBITS {
+		if section.Name == ".stack" {
+			// HACK: this works around a bug in ld.lld from LLVM 10. The linker
+			// marks sections with no input symbols (such as is the case for the
+			// .stack section) as SHT_PROGBITS instead of SHT_NOBITS. While it
+			// doesn't affect the generated binaries (.hex and .bin), it does
+			// affect the reported size.
+			// https://bugs.llvm.org/show_bug.cgi?id=45336
+			// https://reviews.llvm.org/D76981
+			// It has been merged in master, but it has not (yet) been
+			// backported to the LLVM 10 release branch.
+			sumBSS += section.Size
+		} else if section.Type == elf.SHT_NOBITS {
 			sumBSS += section.Size
 		} else if section.Flags&elf.SHF_EXECINSTR != 0 {
 			sumCode += section.Size
@@ -115,7 +128,7 @@ func Sizes(path string) (*ProgramSize, error) {
 	}
 	sort.Sort(symbolList(symbols))
 
-	sizes := map[string]*PackageSize{}
+	sizes := map[string]*packageSize{}
 	var lastSymbolValue uint64
 	for _, symbol := range symbols {
 		symType := elf.ST_TYPE(symbol.Info)
@@ -129,7 +142,7 @@ func Sizes(path string) (*ProgramSize, error) {
 		}
 		pkgSize := sizes[pkgName]
 		if pkgSize == nil {
-			pkgSize = &PackageSize{}
+			pkgSize = &packageSize{}
 			sizes[pkgName] = pkgSize
 		}
 		if lastSymbolValue != symbol.Value || lastSymbolValue == 0 {
@@ -148,7 +161,7 @@ func Sizes(path string) (*ProgramSize, error) {
 		lastSymbolValue = symbol.Value
 	}
 
-	sum := &PackageSize{}
+	sum := &packageSize{}
 	for _, pkg := range sizes {
 		sum.Code += pkg.Code
 		sum.ROData += pkg.ROData
@@ -156,5 +169,5 @@ func Sizes(path string) (*ProgramSize, error) {
 		sum.BSS += pkg.BSS
 	}
 
-	return &ProgramSize{Packages: sizes, Code: sumCode, Data: sumData, BSS: sumBSS, Sum: sum}, nil
+	return &programSize{Packages: sizes, Code: sumCode, Data: sumData, BSS: sumBSS, Sum: sum}, nil
 }

builder/tools-builtin.go

@@ -0,0 +1,54 @@
+// +build byollvm
+
+package builder
+
+import (
+	"errors"
+	"unsafe"
+)
+
+/*
+#cgo CXXFLAGS: -fno-rtti
+#include <stdbool.h>
+#include <stdlib.h>
+bool tinygo_clang_driver(int argc, char **argv);
+bool tinygo_link_elf(int argc, char **argv);
+bool tinygo_link_wasm(int argc, char **argv);
+*/
+import "C"
+
+const hasBuiltinTools = true
+
+// RunTool runs the given tool (such as clang).
+//
+// This version actually runs the tools because TinyGo was compiled while
+// linking statically with LLVM (with the byollvm build tag).
+func RunTool(tool string, args ...string) error {
+	args = append([]string{"tinygo:" + tool}, args...)
+
+	var cflag *C.char
+	buf := C.calloc(C.size_t(len(args)), C.size_t(unsafe.Sizeof(cflag)))
+	defer C.free(buf)
+	cflags := (*[1 << 10]*C.char)(unsafe.Pointer(buf))[:len(args):len(args)]
+	for i, flag := range args {
+		cflag := C.CString(flag)
+		cflags[i] = cflag
+		defer C.free(unsafe.Pointer(cflag))
+	}
+
+	var ok C.bool
+	switch tool {
+	case "clang":
+		ok = C.tinygo_clang_driver(C.int(len(args)), (**C.char)(buf))
+	case "ld.lld":
+		ok = C.tinygo_link_elf(C.int(len(args)), (**C.char)(buf))
+	case "wasm-ld":
+		ok = C.tinygo_link_wasm(C.int(len(args)), (**C.char)(buf))
+	default:
+		return errors.New("unknown tool: " + tool)
+	}
+	if !ok {
+		return errors.New("failed to run tool: " + tool)
+	}
+	return nil
+}

builder/tools-external.go

@@ -0,0 +1,15 @@
+// +build !byollvm
+
+package builder
+
+import "errors"
+
+const hasBuiltinTools = false
+
+// RunTool runs the given tool (such as clang).
+//
+// This version doesn't actually run the tool: TinyGo has not been compiled by
+// statically linking to LLVM.
+func RunTool(tool string, args ...string) error {
+	return errors.New("cannot run tool: " + tool)
+}

builder/tools.go

@@ -0,0 +1,59 @@
+package builder
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// runCCompiler invokes a C compiler with the given arguments.
+func runCCompiler(command string, flags ...string) error {
+	if hasBuiltinTools && command == "clang" {
+		// Compile this with the internal Clang compiler.
+		headerPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
+		if headerPath == "" {
+			return errors.New("could not locate Clang headers")
+		}
+		flags = append(flags, "-I"+headerPath)
+		cmd := exec.Command(os.Args[0], append([]string{"clang"}, flags...)...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		return cmd.Run()
+	}
+
+	// Running some other compiler. Maybe it has been defined in the
+	// commands map (unlikely).
+	if cmdNames, ok := commands[command]; ok {
+		return execCommand(cmdNames, flags...)
+	}
+
+	// Alternatively, run the compiler directly.
+	cmd := exec.Command(command, flags...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
+}
+
+// link invokes a linker with the given name and flags.
+func link(linker string, flags ...string) error {
+	if hasBuiltinTools && (linker == "ld.lld" || linker == "wasm-ld") {
+		// Run command with internal linker.
+		cmd := exec.Command(os.Args[0], append([]string{linker}, flags...)...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		return cmd.Run()
+	}
+
+	// Fall back to external command.
+	if cmdNames, ok := commands[linker]; ok {
+		return execCommand(cmdNames, flags...)
+	}
+
+	cmd := exec.Command(linker, flags...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Dir = goenv.Get("TINYGOROOT")
+	return cmd.Run()
+}

builder/uf2.go

@@ -0,0 +1,151 @@
+package builder
+
+// This file converts firmware files from BIN to UF2 format before flashing.
+//
+// For more information about the UF2 firmware file format, please see:
+// https://github.com/Microsoft/uf2
+//
+//
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io/ioutil"
+	"strconv"
+)
+
+// convertELFFileToUF2File converts an ELF file to a UF2 file.
+func convertELFFileToUF2File(infile, outfile string, uf2FamilyID string) error {
+	// Read the .text segment.
+	targetAddress, data, err := extractROM(infile)
+	if err != nil {
+		return err
+	}
+
+	output, _, err := convertBinToUF2(data, uint32(targetAddress), uf2FamilyID)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(outfile, output, 0644)
+}
+
+// convertBinToUF2 converts the binary bytes in input to UF2 formatted data.
+func convertBinToUF2(input []byte, targetAddr uint32, uf2FamilyID string) ([]byte, int, error) {
+	blocks := split(input, 256)
+	output := make([]byte, 0)
+
+	bl, err := newUF2Block(targetAddr, uf2FamilyID)
+	if err != nil {
+		return nil, 0, err
+	}
+	bl.SetNumBlocks(len(blocks))
+
+	for i := 0; i < len(blocks); i++ {
+		bl.SetBlockNo(i)
+		bl.SetData(blocks[i])
+
+		output = append(output, bl.Bytes()...)
+		bl.IncrementAddress(bl.payloadSize)
+	}
+
+	return output, len(blocks), nil
+}
+
+const (
+	uf2MagicStart0 = 0x0A324655 // "UF2\n"
+	uf2MagicStart1 = 0x9E5D5157 // Randomly selected
+	uf2MagicEnd    = 0x0AB16F30 // Ditto
+)
+
+// uf2Block is the structure used for each UF2 code block sent to device.
+type uf2Block struct {
+	magicStart0 uint32
+	magicStart1 uint32
+	flags       uint32
+	targetAddr  uint32
+	payloadSize uint32
+	blockNo     uint32
+	numBlocks   uint32
+	familyID    uint32
+	data        []uint8
+	magicEnd    uint32
+}
+
+// newUF2Block returns a new uf2Block struct that has been correctly populated
+func newUF2Block(targetAddr uint32, uf2FamilyID string) (*uf2Block, error) {
+	var flags uint32
+	var familyID uint32
+	if uf2FamilyID != "" {
+		flags |= flagFamilyIDPresent
+		v, err := strconv.ParseUint(uf2FamilyID, 0, 32)
+		if err != nil {
+			return nil, err
+		}
+		familyID = uint32(v)
+	}
+	return &uf2Block{magicStart0: uf2MagicStart0,
+		magicStart1: uf2MagicStart1,
+		magicEnd:    uf2MagicEnd,
+		targetAddr:  targetAddr,
+		flags:       flags,
+		familyID:    familyID,
+		payloadSize: 256,
+		data:        make([]byte, 476),
+	}, nil
+}
+
+const (
+	flagFamilyIDPresent = 0x00002000
+)
+
+// Bytes converts the uf2Block to a slice of bytes that can be written to file.
+func (b *uf2Block) Bytes() []byte {
+	buf := bytes.NewBuffer(make([]byte, 0, 512))
+	binary.Write(buf, binary.LittleEndian, b.magicStart0)
+	binary.Write(buf, binary.LittleEndian, b.magicStart1)
+	binary.Write(buf, binary.LittleEndian, b.flags)
+	binary.Write(buf, binary.LittleEndian, b.targetAddr)
+	binary.Write(buf, binary.LittleEndian, b.payloadSize)
+	binary.Write(buf, binary.LittleEndian, b.blockNo)
+	binary.Write(buf, binary.LittleEndian, b.numBlocks)
+	binary.Write(buf, binary.LittleEndian, b.familyID)
+	binary.Write(buf, binary.LittleEndian, b.data)
+	binary.Write(buf, binary.LittleEndian, b.magicEnd)
+
+	return buf.Bytes()
+}
+
+// IncrementAddress moves the target address pointer forward by count bytes.
+func (b *uf2Block) IncrementAddress(count uint32) {
+	b.targetAddr += b.payloadSize
+}
+
+// SetData sets the data to be used for the current block.
+func (b *uf2Block) SetData(d []byte) {
+	b.data = make([]byte, 476)
+	copy(b.data[:], d)
+}
+
+// SetBlockNo sets the current block number to be used.
+func (b *uf2Block) SetBlockNo(bn int) {
+	b.blockNo = uint32(bn)
+}
+
+// SetNumBlocks sets the total number of blocks for this UF2 file.
+func (b *uf2Block) SetNumBlocks(total int) {
+	b.numBlocks = uint32(total)
+}
+
+// split splits a slice of bytes into a slice of byte slices of a specific size limit.
+func split(input []byte, limit int) [][]byte {
+	var block []byte
+	output := make([][]byte, 0, len(input)/limit+1)
+	for len(input) >= limit {
+		block, input = input[:limit], input[limit:]
+		output = append(output, block)
+	}
+	if len(input) > 0 {
+		output = append(output, input[:len(input)])
+	}
+	return output
+}

cgo/cgo_test.go

@@ -0,0 +1,160 @@
+package cgo
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"io/ioutil"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// Pass -update to go test to update the output of the test files.
+var flagUpdate = flag.Bool("update", false, "Update images based on test output.")
+
+// normalizeResult normalizes Go source code that comes out of tests across
+// platforms and Go versions.
+func normalizeResult(result string) string {
+	actual := strings.ReplaceAll(result, "\r\n", "\n")
+
+	// Make sure all functions are wrapped, even those that would otherwise be
+	// single-line functions. This is necessary because Go 1.14 changed the way
+	// such functions are wrapped and it's important to have consistent test
+	// results.
+	re := regexp.MustCompile(`func \((.+)\)( .*?) +{ (.+) }`)
+	actual = re.ReplaceAllString(actual, "func ($1)$2 {\n\t$3\n}")
+
+	return actual
+}
+
+func TestCGo(t *testing.T) {
+	var cflags = []string{"--target=armv6m-none-eabi"}
+
+	for _, name := range []string{"basic", "errors", "types", "flags", "const"} {
+		name := name // avoid a race condition
+		t.Run(name, func(t *testing.T) {
+			// Skip tests that require specific Go version.
+			if name == "errors" {
+				ok := false
+				for _, version := range build.Default.ReleaseTags {
+					if version == "go1.16" {
+						ok = true
+						break
+					}
+				}
+				if !ok {
+					t.Skip("Results for errors test are only valid for Go 1.16+")
+				}
+			}
+
+			// Read the AST in memory.
+			path := filepath.Join("testdata", name+".go")
+			fset := token.NewFileSet()
+			f, err := parser.ParseFile(fset, path, nil, parser.ParseComments)
+			if err != nil {
+				t.Fatal("could not parse Go source file:", err)
+			}
+
+			// Process the AST with CGo.
+			cgoAST, _, _, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags)
+
+			// Check the AST for type errors.
+			var typecheckErrors []error
+			config := types.Config{
+				Error: func(err error) {
+					typecheckErrors = append(typecheckErrors, err)
+				},
+				Importer: simpleImporter{},
+				Sizes:    types.SizesFor("gccgo", "arm"),
+			}
+			_, err = config.Check("", fset, []*ast.File{f, cgoAST}, nil)
+			if err != nil && len(typecheckErrors) == 0 {
+				// Only report errors when no type errors are found (an
+				// unexpected condition).
+				t.Error(err)
+			}
+
+			// Store the (formatted) output in a buffer. Format it, so it
+			// becomes easier to read (and will hopefully change less with CGo
+			// changes).
+			buf := &bytes.Buffer{}
+			if len(cgoErrors) != 0 {
+				buf.WriteString("// CGo errors:\n")
+				for _, err := range cgoErrors {
+					buf.WriteString(formatDiagnostic(err))
+				}
+				buf.WriteString("\n")
+			}
+			if len(typecheckErrors) != 0 {
+				buf.WriteString("// Type checking errors after CGo processing:\n")
+				for _, err := range typecheckErrors {
+					buf.WriteString(formatDiagnostic(err))
+				}
+				buf.WriteString("\n")
+			}
+			err = format.Node(buf, fset, cgoAST)
+			if err != nil {
+				t.Errorf("could not write out CGo AST: %v", err)
+			}
+			actual := normalizeResult(string(buf.Bytes()))
+
+			// Read the file with the expected output, to compare against.
+			outfile := filepath.Join("testdata", name+".out.go")
+			expectedBytes, err := ioutil.ReadFile(outfile)
+			if err != nil {
+				t.Fatalf("could not read expected output: %v", err)
+			}
+			expected := strings.ReplaceAll(string(expectedBytes), "\r\n", "\n")
+
+			// Check whether the output is as expected.
+			if expected != actual {
+				// It is not. Test failed.
+				if *flagUpdate {
+					// Update the file with the expected data.
+					err := ioutil.WriteFile(outfile, []byte(actual), 0666)
+					if err != nil {
+						t.Error("could not write updated output file:", err)
+					}
+					return
+				}
+				t.Errorf("output did not match:\n%s", string(actual))
+			}
+		})
+	}
+}
+
+// simpleImporter implements the types.Importer interface, but only allows
+// importing the unsafe package.
+type simpleImporter struct {
+}
+
+// Import implements the Importer interface. For testing usage only: it only
+// supports importing the unsafe package.
+func (i simpleImporter) Import(path string) (*types.Package, error) {
+	switch path {
+	case "unsafe":
+		return types.Unsafe, nil
+	default:
+		return nil, fmt.Errorf("importer not implemented for package %s", path)
+	}
+}
+
+// formatDiagnostics formats the error message to be an indented comment. It
+// also fixes Windows path name issues (backward slashes).
+func formatDiagnostic(err error) string {
+	msg := err.Error()
+	if runtime.GOOS == "windows" {
+		// Fix Windows path slashes.
+		msg = strings.ReplaceAll(msg, "testdata\\", "testdata/")
+	}
+	return "//     " + msg + "\n"
+}

cgo/const.go

@@ -0,0 +1,218 @@
+package cgo
+
+// This file implements a parser of a subset of the C language, just enough to
+// parse common #define statements to Go constant expressions.
+
+import (
+	"fmt"
+	"go/ast"
+	"go/scanner"
+	"go/token"
+	"strings"
+)
+
+// parseConst parses the given string as a C constant.
+func parseConst(pos token.Pos, fset *token.FileSet, value string) (ast.Expr, *scanner.Error) {
+	t := newTokenizer(pos, fset, value)
+	expr, err := parseConstExpr(t)
+	if t.token != token.EOF {
+		return nil, &scanner.Error{
+			Pos: t.fset.Position(t.pos),
+			Msg: "unexpected token " + t.token.String(),
+		}
+	}
+	return expr, err
+}
+
+// parseConstExpr parses a stream of C tokens to a Go expression.
+func parseConstExpr(t *tokenizer) (ast.Expr, *scanner.Error) {
+	switch t.token {
+	case token.LPAREN:
+		lparen := t.pos
+		t.Next()
+		x, err := parseConstExpr(t)
+		if err != nil {
+			return nil, err
+		}
+		if t.token != token.RPAREN {
+			return nil, unexpectedToken(t, token.RPAREN)
+		}
+		expr := &ast.ParenExpr{
+			Lparen: lparen,
+			X:      x,
+			Rparen: t.pos,
+		}
+		t.Next()
+		return expr, nil
+	case token.INT, token.FLOAT, token.STRING, token.CHAR:
+		expr := &ast.BasicLit{
+			ValuePos: t.pos,
+			Kind:     t.token,
+			Value:    t.value,
+		}
+		t.Next()
+		return expr, nil
+	case token.IDENT:
+		expr := &ast.Ident{
+			NamePos: t.pos,
+			Name:    "C." + t.value,
+		}
+		t.Next()
+		return expr, nil
+	case token.EOF:
+		return nil, &scanner.Error{
+			Pos: t.fset.Position(t.pos),
+			Msg: "empty constant",
+		}
+	default:
+		return nil, &scanner.Error{
+			Pos: t.fset.Position(t.pos),
+			Msg: fmt.Sprintf("unexpected token %s", t.token),
+		}
+	}
+}
+
+// unexpectedToken returns an error of the form "unexpected token FOO, expected
+// BAR".
+func unexpectedToken(t *tokenizer, expected token.Token) *scanner.Error {
+	return &scanner.Error{
+		Pos: t.fset.Position(t.pos),
+		Msg: fmt.Sprintf("unexpected token %s, expected %s", t.token, expected),
+	}
+}
+
+// tokenizer reads C source code and converts it to Go tokens.
+type tokenizer struct {
+	pos   token.Pos
+	fset  *token.FileSet
+	token token.Token
+	value string
+	buf   string
+}
+
+// newTokenizer initializes a new tokenizer, positioned at the first token in
+// the string.
+func newTokenizer(start token.Pos, fset *token.FileSet, buf string) *tokenizer {
+	t := &tokenizer{
+		pos:   start,
+		fset:  fset,
+		buf:   buf,
+		token: token.ILLEGAL,
+	}
+	t.Next() // Parse the first token.
+	return t
+}
+
+// Next consumes the next token in the stream. There is no return value, read
+// the next token from the pos, token and value properties.
+func (t *tokenizer) Next() {
+	t.pos += token.Pos(len(t.value))
+	for {
+		if len(t.buf) == 0 {
+			t.token = token.EOF
+			return
+		}
+		c := t.buf[0]
+		switch {
+		case c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v':
+			// Skip whitespace.
+			// Based on this source, not sure whether it represents C whitespace:
+			// https://en.cppreference.com/w/cpp/string/byte/isspace
+			t.pos++
+			t.buf = t.buf[1:]
+		case c == '(' || c == ')':
+			// Single-character tokens.
+			switch c {
+			case '(':
+				t.token = token.LPAREN
+			case ')':
+				t.token = token.RPAREN
+			}
+			t.value = t.buf[:1]
+			t.buf = t.buf[1:]
+			return
+		case c >= '0' && c <= '9':
+			// Numeric constant (int, float, etc.).
+			// Find the last non-numeric character.
+			tokenLen := len(t.buf)
+			hasDot := false
+			for i, c := range t.buf {
+				if c == '.' {
+					hasDot = true
+				}
+				if c >= '0' && c <= '9' || c == '.' || c == '_' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' {
+					tokenLen = i + 1
+				} else {
+					break
+				}
+			}
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			if hasDot {
+				// Integer constants are more complicated than this but this is
+				// a close approximation.
+				// https://en.cppreference.com/w/cpp/language/integer_literal
+				t.token = token.FLOAT
+				t.value = strings.TrimRight(t.value, "f")
+			} else {
+				t.token = token.INT
+				t.value = strings.TrimRight(t.value, "uUlL")
+			}
+			return
+		case c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' || c == '_':
+			// Identifier. Find all remaining tokens that are part of this
+			// identifier.
+			tokenLen := len(t.buf)
+			for i, c := range t.buf {
+				if c >= '0' && c <= '9' || c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' || c == '_' {
+					tokenLen = i + 1
+				} else {
+					break
+				}
+			}
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			t.token = token.IDENT
+			return
+		case c == '"':
+			// String constant. Find the first '"' character that is not
+			// preceded by a backslash.
+			escape := false
+			tokenLen := len(t.buf)
+			for i, c := range t.buf {
+				if i != 0 && c == '"' && !escape {
+					tokenLen = i + 1
+					break
+				}
+				if !escape {
+					escape = c == '\\'
+				}
+			}
+			t.token = token.STRING
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			return
+		case c == '\'':
+			// Char (rune) constant. Find the first '\'' character that is not
+			// preceded by a backslash.
+			escape := false
+			tokenLen := len(t.buf)
+			for i, c := range t.buf {
+				if i != 0 && c == '\'' && !escape {
+					tokenLen = i + 1
+					break
+				}
+				if !escape {
+					escape = c == '\\'
+				}
+			}
+			t.token = token.CHAR
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			return
+		default:
+			t.token = token.ILLEGAL
+			return
+		}
+	}
+}

cgo/const_test.go

@@ -0,0 +1,60 @@
+package cgo
+
+import (
+	"bytes"
+	"go/format"
+	"go/token"
+	"strings"
+	"testing"
+)
+
+func TestParseConst(t *testing.T) {
+	// Test converting a C constant to a Go constant.
+	for _, tc := range []struct {
+		C  string
+		Go string
+	}{
+		{`5`, `5`},
+		{`(5)`, `(5)`},
+		{`(((5)))`, `(5)`},
+		{`)`, `error: 1:1: unexpected token )`},
+		{`5)`, `error: 1:2: unexpected token )`},
+		{"  \t)", `error: 1:4: unexpected token )`},
+		{`5.8f`, `5.8`},
+		{`foo`, `C.foo`},
+		{``, `error: 1:1: empty constant`}, // empty constants not allowed in Go
+		{`"foo"`, `"foo"`},
+		{`"a\\n"`, `"a\\n"`},
+		{`"a\n"`, `"a\n"`},
+		{`"a\""`, `"a\""`},
+		{`'a'`, `'a'`},
+		{`0b10`, `0b10`},
+		{`0x1234_5678`, `0x1234_5678`},
+		{`5 5`, `error: 1:3: unexpected token INT`}, // test for a bugfix
+	} {
+		fset := token.NewFileSet()
+		startPos := fset.AddFile("", -1, 1000).Pos(0)
+		expr, err := parseConst(startPos, fset, tc.C)
+		s := "<invalid>"
+		if err != nil {
+			if !strings.HasPrefix(tc.Go, "error: ") {
+				t.Errorf("expected value %#v for C constant %#v but got error %#v", tc.Go, tc.C, err.Error())
+				continue
+			}
+			s = "error: " + err.Error()
+		} else if expr != nil {
+			// Serialize the Go constant to a string, for more readable test
+			// cases.
+			buf := &bytes.Buffer{}
+			err := format.Node(buf, fset, expr)
+			if err != nil {
+				t.Errorf("could not format expr from C constant %#v: %v", tc.C, err)
+				continue
+			}
+			s = buf.String()
+		}
+		if s != tc.Go {
+			t.Errorf("C constant %#v was parsed to %#v while expecting %#v", tc.C, s, tc.Go)
+		}
+	}
+}

cgo/libclang.go

@@ -0,0 +1,809 @@
+package cgo
+
+// This file parses a fragment of C with libclang and stores the result for AST
+// modification. It does not touch the AST itself.
+
+import (
+	"crypto/sha512"
+	"fmt"
+	"go/ast"
+	"go/scanner"
+	"go/token"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"unsafe"
+)
+
+/*
+#include <clang-c/Index.h> // if this fails, install libclang-10-dev
+#include <stdlib.h>
+#include <stdint.h>
+
+// This struct should be ABI-compatible on all platforms (uintptr_t has the same
+// alignment etc. as void*) but does not include void* pointers that are not
+// always real pointers.
+// The Go garbage collector assumes that all non-nil pointer-typed integers are
+// actually pointers. This is not always true, as data[1] often contains 0x1,
+// which is clearly not a valid pointer. Usually the GC won't catch this issue,
+// but occasionally it will leading to a crash with a vague error message.
+typedef struct {
+	enum CXCursorKind kind;
+	int xdata;
+	uintptr_t data[3];
+} GoCXCursor;
+
+// Forwarding functions. They are implemented in libclang_stubs.c and forward to
+// the real functions without doing anything else, thus they are entirely
+// compatible with the versions without tinygo_ prefix. The only difference is
+// the CXCursor type, which has been replaced with GoCXCursor.
+GoCXCursor tinygo_clang_getTranslationUnitCursor(CXTranslationUnit tu);
+unsigned tinygo_clang_visitChildren(GoCXCursor parent, CXCursorVisitor visitor, CXClientData client_data);
+CXString tinygo_clang_getCursorSpelling(GoCXCursor c);
+enum CXCursorKind tinygo_clang_getCursorKind(GoCXCursor c);
+CXType tinygo_clang_getCursorType(GoCXCursor c);
+GoCXCursor tinygo_clang_getTypeDeclaration(CXType t);
+CXType tinygo_clang_getTypedefDeclUnderlyingType(GoCXCursor c);
+CXType tinygo_clang_getCursorResultType(GoCXCursor c);
+int tinygo_clang_Cursor_getNumArguments(GoCXCursor c);
+GoCXCursor tinygo_clang_Cursor_getArgument(GoCXCursor c, unsigned i);
+CXSourceLocation tinygo_clang_getCursorLocation(GoCXCursor c);
+CXSourceRange tinygo_clang_getCursorExtent(GoCXCursor c);
+CXTranslationUnit tinygo_clang_Cursor_getTranslationUnit(GoCXCursor c);
+long long tinygo_clang_getEnumConstantDeclValue(GoCXCursor c);
+CXType tinygo_clang_getEnumDeclIntegerType(GoCXCursor c);
+unsigned tinygo_clang_Cursor_isBitField(GoCXCursor c);
+
+int tinygo_clang_globals_visitor(GoCXCursor c, GoCXCursor parent, CXClientData client_data);
+int tinygo_clang_struct_visitor(GoCXCursor c, GoCXCursor parent, CXClientData client_data);
+int tinygo_clang_enum_visitor(GoCXCursor c, GoCXCursor parent, CXClientData client_data);
+void tinygo_clang_inclusion_visitor(CXFile included_file, CXSourceLocation *inclusion_stack, unsigned include_len, CXClientData client_data);
+*/
+import "C"
+
+// storedRefs stores references to types, used for clang_visitChildren.
+var storedRefs refMap
+
+var diagnosticSeverity = [...]string{
+	C.CXDiagnostic_Ignored: "ignored",
+	C.CXDiagnostic_Note:    "note",
+	C.CXDiagnostic_Warning: "warning",
+	C.CXDiagnostic_Error:   "error",
+	C.CXDiagnostic_Fatal:   "fatal",
+}
+
+func (p *cgoPackage) parseFragment(fragment string, cflags []string, posFilename string, posLine int) {
+	index := C.clang_createIndex(0, 0)
+	defer C.clang_disposeIndex(index)
+
+	// pretend to be a .c file
+	filenameC := C.CString(posFilename + "!cgo.c")
+	defer C.free(unsafe.Pointer(filenameC))
+
+	// fix up error locations
+	fragment = fmt.Sprintf("# %d %#v\n", posLine+1, posFilename) + fragment
+
+	fragmentC := C.CString(fragment)
+	defer C.free(unsafe.Pointer(fragmentC))
+
+	unsavedFile := C.struct_CXUnsavedFile{
+		Filename: filenameC,
+		Length:   C.ulong(len(fragment)),
+		Contents: fragmentC,
+	}
+
+	// convert Go slice of strings to C array of strings.
+	cmdargsC := C.malloc(C.size_t(len(cflags)) * C.size_t(unsafe.Sizeof(uintptr(0))))
+	defer C.free(cmdargsC)
+	cmdargs := (*[1 << 16]*C.char)(cmdargsC)
+	for i, cflag := range cflags {
+		s := C.CString(cflag)
+		cmdargs[i] = s
+		defer C.free(unsafe.Pointer(s))
+	}
+
+	var unit C.CXTranslationUnit
+	errCode := C.clang_parseTranslationUnit2(
+		index,
+		filenameC,
+		(**C.char)(cmdargsC), C.int(len(cflags)), // command line args
+		&unsavedFile, 1, // unsaved files
+		C.CXTranslationUnit_DetailedPreprocessingRecord,
+		&unit)
+	if errCode != 0 {
+		// This is probably a bug in the usage of libclang.
+		panic("cgo: failed to parse source with libclang")
+	}
+	defer C.clang_disposeTranslationUnit(unit)
+
+	// Report parser and type errors.
+	if numDiagnostics := int(C.clang_getNumDiagnostics(unit)); numDiagnostics != 0 {
+		addDiagnostic := func(diagnostic C.CXDiagnostic) {
+			spelling := getString(C.clang_getDiagnosticSpelling(diagnostic))
+			severity := diagnosticSeverity[C.clang_getDiagnosticSeverity(diagnostic)]
+			location := C.clang_getDiagnosticLocation(diagnostic)
+			pos := p.getClangLocationPosition(location, unit)
+			p.addError(pos, severity+": "+spelling)
+		}
+		for i := 0; i < numDiagnostics; i++ {
+			diagnostic := C.clang_getDiagnostic(unit, C.uint(i))
+			addDiagnostic(diagnostic)
+
+			// Child diagnostics (like notes on redefinitions).
+			diagnostics := C.clang_getChildDiagnostics(diagnostic)
+			for j := 0; j < int(C.clang_getNumDiagnosticsInSet(diagnostics)); j++ {
+				addDiagnostic(C.clang_getDiagnosticInSet(diagnostics, C.uint(j)))
+			}
+		}
+	}
+
+	// Extract information required by CGo.
+	ref := storedRefs.Put(p)
+	defer storedRefs.Remove(ref)
+	cursor := C.tinygo_clang_getTranslationUnitCursor(unit)
+	C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_globals_visitor), C.CXClientData(ref))
+
+	// Determine files read during CGo processing, for caching.
+	inclusionCallback := func(includedFile C.CXFile) {
+		// Get full file path.
+		path := getString(C.clang_getFileName(includedFile))
+
+		// Get contents of file (that should be in-memory).
+		size := C.size_t(0)
+		rawData := C.clang_getFileContents(unit, includedFile, &size)
+		if rawData == nil {
+			// Sanity check. This should (hopefully) never trigger.
+			panic("libclang: file contents was not loaded")
+		}
+		data := (*[1 << 24]byte)(unsafe.Pointer(rawData))[:size]
+
+		// Hash the contents if it isn't hashed yet.
+		if _, ok := p.visitedFiles[path]; !ok {
+			// already stored
+			sum := sha512.Sum512_224(data)
+			p.visitedFiles[path] = sum[:]
+		}
+	}
+	inclusionCallbackRef := storedRefs.Put(inclusionCallback)
+	defer storedRefs.Remove(inclusionCallbackRef)
+	C.clang_getInclusions(unit, C.CXInclusionVisitor(C.tinygo_clang_inclusion_visitor), C.CXClientData(inclusionCallbackRef))
+}
+
+//export tinygo_clang_globals_visitor
+func tinygo_clang_globals_visitor(c, parent C.GoCXCursor, client_data C.CXClientData) C.int {
+	p := storedRefs.Get(unsafe.Pointer(client_data)).(*cgoPackage)
+	kind := C.tinygo_clang_getCursorKind(c)
+	pos := p.getCursorPosition(c)
+	switch kind {
+	case C.CXCursor_FunctionDecl:
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		cursorType := C.tinygo_clang_getCursorType(c)
+		numArgs := int(C.tinygo_clang_Cursor_getNumArguments(c))
+		fn := &functionInfo{
+			pos:      pos,
+			variadic: C.clang_isFunctionTypeVariadic(cursorType) != 0,
+		}
+		p.functions[name] = fn
+		for i := 0; i < numArgs; i++ {
+			arg := C.tinygo_clang_Cursor_getArgument(c, C.uint(i))
+			argName := getString(C.tinygo_clang_getCursorSpelling(arg))
+			argType := C.clang_getArgType(cursorType, C.uint(i))
+			if argName == "" {
+				argName = "$" + strconv.Itoa(i)
+			}
+			fn.args = append(fn.args, paramInfo{
+				name:     argName,
+				typeExpr: p.makeASTType(argType, pos),
+			})
+		}
+		resultType := C.tinygo_clang_getCursorResultType(c)
+		if resultType.kind != C.CXType_Void {
+			fn.results = &ast.FieldList{
+				List: []*ast.Field{
+					&ast.Field{
+						Type: p.makeASTType(resultType, pos),
+					},
+				},
+			}
+		}
+	case C.CXCursor_StructDecl:
+		typ := C.tinygo_clang_getCursorType(c)
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols["struct_"+name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		p.makeASTType(typ, pos)
+	case C.CXCursor_TypedefDecl:
+		typedefType := C.tinygo_clang_getCursorType(c)
+		name := getString(C.clang_getTypedefName(typedefType))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		p.makeASTType(typedefType, pos)
+	case C.CXCursor_VarDecl:
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		cursorType := C.tinygo_clang_getCursorType(c)
+		p.globals[name] = globalInfo{
+			typeExpr: p.makeASTType(cursorType, pos),
+			pos:      pos,
+		}
+	case C.CXCursor_MacroDefinition:
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		sourceRange := C.tinygo_clang_getCursorExtent(c)
+		start := C.clang_getRangeStart(sourceRange)
+		end := C.clang_getRangeEnd(sourceRange)
+		var file, endFile C.CXFile
+		var startOffset, endOffset C.unsigned
+		C.clang_getExpansionLocation(start, &file, nil, nil, &startOffset)
+		if file == nil {
+			p.addError(pos, "internal error: could not find file where macro is defined")
+			break
+		}
+		C.clang_getExpansionLocation(end, &endFile, nil, nil, &endOffset)
+		if file != endFile {
+			p.addError(pos, "internal error: expected start and end location of a macro to be in the same file")
+			break
+		}
+		if startOffset > endOffset {
+			p.addError(pos, "internal error: start offset of macro is after end offset")
+			break
+		}
+
+		// read file contents and extract the relevant byte range
+		tu := C.tinygo_clang_Cursor_getTranslationUnit(c)
+		var size C.size_t
+		sourcePtr := C.clang_getFileContents(tu, file, &size)
+		if endOffset >= C.uint(size) {
+			p.addError(pos, "internal error: end offset of macro lies after end of file")
+			break
+		}
+		source := string(((*[1 << 28]byte)(unsafe.Pointer(sourcePtr)))[startOffset:endOffset:endOffset])
+		if !strings.HasPrefix(source, name) {
+			p.addError(pos, fmt.Sprintf("internal error: expected macro value to start with %#v, got %#v", name, source))
+			break
+		}
+		value := source[len(name):]
+		// Try to convert this #define into a Go constant expression.
+		expr, scannerError := parseConst(pos+token.Pos(len(name)), p.fset, value)
+		if scannerError != nil {
+			p.errors = append(p.errors, *scannerError)
+		}
+		if expr != nil {
+			// Parsing was successful.
+			p.constants[name] = constantInfo{expr, pos}
+		}
+	case C.CXCursor_EnumDecl:
+		// Visit all enums, because the fields may be used even when the enum
+		// type itself is not.
+		typ := C.tinygo_clang_getCursorType(c)
+		p.makeASTType(typ, pos)
+	}
+	return C.CXChildVisit_Continue
+}
+
+func getString(clangString C.CXString) (s string) {
+	rawString := C.clang_getCString(clangString)
+	s = C.GoString(rawString)
+	C.clang_disposeString(clangString)
+	return
+}
+
+// getCursorPosition returns a usable token.Pos from a libclang cursor.
+func (p *cgoPackage) getCursorPosition(cursor C.GoCXCursor) token.Pos {
+	return p.getClangLocationPosition(C.tinygo_clang_getCursorLocation(cursor), C.tinygo_clang_Cursor_getTranslationUnit(cursor))
+}
+
+// getClangLocationPosition returns a usable token.Pos based on a libclang
+// location and translation unit. If the file for this cursor has not been seen
+// before, it is read from libclang (which already has the file in memory) and
+// added to the token.FileSet.
+func (p *cgoPackage) getClangLocationPosition(location C.CXSourceLocation, tu C.CXTranslationUnit) token.Pos {
+	var file C.CXFile
+	var line C.unsigned
+	var column C.unsigned
+	var offset C.unsigned
+	C.clang_getExpansionLocation(location, &file, &line, &column, &offset)
+	if line == 0 || file == nil {
+		// Invalid token.
+		return token.NoPos
+	}
+	filename := getString(C.clang_getFileName(file))
+	if _, ok := p.tokenFiles[filename]; !ok {
+		// File has not been seen before in this package, add line information
+		// now by reading the file from libclang.
+		var size C.size_t
+		sourcePtr := C.clang_getFileContents(tu, file, &size)
+		source := ((*[1 << 28]byte)(unsafe.Pointer(sourcePtr)))[:size:size]
+		lines := []int{0}
+		for i := 0; i < len(source)-1; i++ {
+			if source[i] == '\n' {
+				lines = append(lines, i+1)
+			}
+		}
+		f := p.fset.AddFile(filename, -1, int(size))
+		f.SetLines(lines)
+		p.tokenFiles[filename] = f
+	}
+	positionFile := p.tokenFiles[filename]
+
+	// Check for alternative line/column information (set with a line directive).
+	var filename2String C.CXString
+	var line2 C.unsigned
+	var column2 C.unsigned
+	C.clang_getPresumedLocation(location, &filename2String, &line2, &column2)
+	filename2 := getString(filename2String)
+	if filename2 != filename || line2 != line || column2 != column {
+		// The location was changed with a preprocessor directive.
+		// TODO: this only works for locations that are added in order. Adding
+		// line/column info to a file that already has line/column info after
+		// the given offset is ignored.
+		positionFile.AddLineColumnInfo(int(offset), filename2, int(line2), int(column2))
+	}
+
+	return positionFile.Pos(int(offset))
+}
+
+// addError is a utility function to add an error to the list of errors. It will
+// convert the token position to a line/column position first, and call
+// addErrorAt.
+func (p *cgoPackage) addError(pos token.Pos, msg string) {
+	p.addErrorAt(p.fset.PositionFor(pos, true), msg)
+}
+
+// addErrorAfter is like addError, but adds the text `after` to the source
+// location.
+func (p *cgoPackage) addErrorAfter(pos token.Pos, after, msg string) {
+	position := p.fset.PositionFor(pos, true)
+	lines := strings.Split(after, "\n")
+	if len(lines) != 1 {
+		// Adjust lines.
+		// For why we can't just do pos+token.Pos(len(after)), see:
+		// https://github.com/golang/go/issues/35803
+		position.Line += len(lines) - 1
+		position.Column = len(lines[len(lines)-1]) + 1
+	} else {
+		position.Column += len(after)
+	}
+	p.addErrorAt(position, msg)
+}
+
+// addErrorAt is a utility function to add an error to the list of errors.
+func (p *cgoPackage) addErrorAt(position token.Position, msg string) {
+	if filepath.IsAbs(position.Filename) {
+		// Relative paths for readability, like other Go parser errors.
+		relpath, err := filepath.Rel(p.dir, position.Filename)
+		if err == nil {
+			position.Filename = relpath
+		}
+	}
+	p.errors = append(p.errors, scanner.Error{
+		Pos: position,
+		Msg: msg,
+	})
+}
+
+// makeASTType return the ast.Expr for the given libclang type. In other words,
+// it converts a libclang type to a type in the Go AST.
+func (p *cgoPackage) makeASTType(typ C.CXType, pos token.Pos) ast.Expr {
+	var typeName string
+	switch typ.kind {
+	case C.CXType_Char_S, C.CXType_Char_U:
+		typeName = "C.char"
+	case C.CXType_SChar:
+		typeName = "C.schar"
+	case C.CXType_UChar:
+		typeName = "C.uchar"
+	case C.CXType_Short:
+		typeName = "C.short"
+	case C.CXType_UShort:
+		typeName = "C.ushort"
+	case C.CXType_Int:
+		typeName = "C.int"
+	case C.CXType_UInt:
+		typeName = "C.uint"
+	case C.CXType_Long:
+		typeName = "C.long"
+	case C.CXType_ULong:
+		typeName = "C.ulong"
+	case C.CXType_LongLong:
+		typeName = "C.longlong"
+	case C.CXType_ULongLong:
+		typeName = "C.ulonglong"
+	case C.CXType_Bool:
+		typeName = "bool"
+	case C.CXType_Float, C.CXType_Double, C.CXType_LongDouble:
+		switch C.clang_Type_getSizeOf(typ) {
+		case 4:
+			typeName = "float32"
+		case 8:
+			typeName = "float64"
+		default:
+			// Don't do anything, rely on the fallback code to show a somewhat
+			// sensible error message like "undeclared name: C.long double".
+		}
+	case C.CXType_Complex:
+		switch C.clang_Type_getSizeOf(typ) {
+		case 8:
+			typeName = "complex64"
+		case 16:
+			typeName = "complex128"
+		}
+	case C.CXType_Pointer:
+		pointeeType := C.clang_getPointeeType(typ)
+		if pointeeType.kind == C.CXType_Void {
+			// void* type is translated to Go as unsafe.Pointer
+			return &ast.SelectorExpr{
+				X: &ast.Ident{
+					NamePos: pos,
+					Name:    "unsafe",
+				},
+				Sel: &ast.Ident{
+					NamePos: pos,
+					Name:    "Pointer",
+				},
+			}
+		}
+		return &ast.StarExpr{
+			Star: pos,
+			X:    p.makeASTType(pointeeType, pos),
+		}
+	case C.CXType_ConstantArray:
+		return &ast.ArrayType{
+			Lbrack: pos,
+			Len: &ast.BasicLit{
+				ValuePos: pos,
+				Kind:     token.INT,
+				Value:    strconv.FormatInt(int64(C.clang_getArraySize(typ)), 10),
+			},
+			Elt: p.makeASTType(C.clang_getElementType(typ), pos),
+		}
+	case C.CXType_FunctionProto:
+		// Be compatible with gc, which uses the *[0]byte type for function
+		// pointer types.
+		// Return type [0]byte because this is a function type, not a pointer to
+		// this function type.
+		return &ast.ArrayType{
+			Lbrack: pos,
+			Len: &ast.BasicLit{
+				ValuePos: pos,
+				Kind:     token.INT,
+				Value:    "0",
+			},
+			Elt: &ast.Ident{
+				NamePos: pos,
+				Name:    "byte",
+			},
+		}
+	case C.CXType_Typedef:
+		name := getString(C.clang_getTypedefName(typ))
+		if _, ok := p.typedefs[name]; !ok {
+			p.typedefs[name] = nil // don't recurse
+			c := C.tinygo_clang_getTypeDeclaration(typ)
+			underlyingType := C.tinygo_clang_getTypedefDeclUnderlyingType(c)
+			expr := p.makeASTType(underlyingType, pos)
+			if strings.HasPrefix(name, "_Cgo_") {
+				expr := expr.(*ast.Ident)
+				typeSize := C.clang_Type_getSizeOf(underlyingType)
+				switch expr.Name {
+				case "C.char":
+					if typeSize != 1 {
+						// This happens for some very special purpose architectures
+						// (DSPs etc.) that are not currently targeted.
+						// https://www.embecosm.com/2017/04/18/non-8-bit-char-support-in-clang-and-llvm/
+						p.addError(pos, fmt.Sprintf("unknown char width: %d", typeSize))
+					}
+					switch underlyingType.kind {
+					case C.CXType_Char_S:
+						expr.Name = "int8"
+					case C.CXType_Char_U:
+						expr.Name = "uint8"
+					}
+				case "C.schar", "C.short", "C.int", "C.long", "C.longlong":
+					switch typeSize {
+					case 1:
+						expr.Name = "int8"
+					case 2:
+						expr.Name = "int16"
+					case 4:
+						expr.Name = "int32"
+					case 8:
+						expr.Name = "int64"
+					}
+				case "C.uchar", "C.ushort", "C.uint", "C.ulong", "C.ulonglong":
+					switch typeSize {
+					case 1:
+						expr.Name = "uint8"
+					case 2:
+						expr.Name = "uint16"
+					case 4:
+						expr.Name = "uint32"
+					case 8:
+						expr.Name = "uint64"
+					}
+				}
+			}
+			p.typedefs[name] = &typedefInfo{
+				typeExpr: expr,
+				pos:      pos,
+			}
+		}
+		return &ast.Ident{
+			NamePos: pos,
+			Name:    "C." + name,
+		}
+	case C.CXType_Elaborated:
+		underlying := C.clang_Type_getNamedType(typ)
+		switch underlying.kind {
+		case C.CXType_Record:
+			return p.makeASTType(underlying, pos)
+		case C.CXType_Enum:
+			return p.makeASTType(underlying, pos)
+		default:
+			typeKindSpelling := getString(C.clang_getTypeKindSpelling(underlying.kind))
+			p.addError(pos, fmt.Sprintf("unknown elaborated type (libclang type kind %s)", typeKindSpelling))
+			typeName = "<unknown>"
+		}
+	case C.CXType_Record:
+		cursor := C.tinygo_clang_getTypeDeclaration(typ)
+		name := getString(C.tinygo_clang_getCursorSpelling(cursor))
+		var cgoRecordPrefix string
+		switch C.tinygo_clang_getCursorKind(cursor) {
+		case C.CXCursor_StructDecl:
+			cgoRecordPrefix = "struct_"
+		case C.CXCursor_UnionDecl:
+			cgoRecordPrefix = "union_"
+		default:
+			// makeASTRecordType will create an appropriate error.
+			cgoRecordPrefix = "record_"
+		}
+		if name == "" {
+			// Anonymous record, probably inside a typedef.
+			typeInfo := p.makeASTRecordType(cursor, pos)
+			if typeInfo.bitfields != nil || typeInfo.unionSize != 0 {
+				// This record is a union or is a struct with bitfields, so we
+				// have to declare it as a named type (for getters/setters to
+				// work).
+				p.anonStructNum++
+				cgoName := cgoRecordPrefix + strconv.Itoa(p.anonStructNum)
+				p.elaboratedTypes[cgoName] = typeInfo
+				return &ast.Ident{
+					NamePos: pos,
+					Name:    "C." + cgoName,
+				}
+			}
+			return typeInfo.typeExpr
+		} else {
+			cgoName := cgoRecordPrefix + name
+			if _, ok := p.elaboratedTypes[cgoName]; !ok {
+				p.elaboratedTypes[cgoName] = nil // predeclare (to avoid endless recursion)
+				p.elaboratedTypes[cgoName] = p.makeASTRecordType(cursor, pos)
+			}
+			return &ast.Ident{
+				NamePos: pos,
+				Name:    "C." + cgoName,
+			}
+		}
+	case C.CXType_Enum:
+		cursor := C.tinygo_clang_getTypeDeclaration(typ)
+		name := getString(C.tinygo_clang_getCursorSpelling(cursor))
+		underlying := C.tinygo_clang_getEnumDeclIntegerType(cursor)
+		if name == "" {
+			// anonymous enum
+			ref := storedRefs.Put(p)
+			defer storedRefs.Remove(ref)
+			C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_enum_visitor), C.CXClientData(ref))
+			return p.makeASTType(underlying, pos)
+		} else {
+			// named enum
+			if _, ok := p.enums[name]; !ok {
+				ref := storedRefs.Put(p)
+				defer storedRefs.Remove(ref)
+				C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_enum_visitor), C.CXClientData(ref))
+				p.enums[name] = enumInfo{
+					typeExpr: p.makeASTType(underlying, pos),
+					pos:      pos,
+				}
+			}
+			return &ast.Ident{
+				NamePos: pos,
+				Name:    "C.enum_" + name,
+			}
+		}
+	}
+	if typeName == "" {
+		// Report this as an error.
+		typeSpelling := getString(C.clang_getTypeSpelling(typ))
+		typeKindSpelling := getString(C.clang_getTypeKindSpelling(typ.kind))
+		p.addError(pos, fmt.Sprintf("unknown C type: %v (libclang type kind %s)", typeSpelling, typeKindSpelling))
+		typeName = "C.<unknown>"
+	}
+	return &ast.Ident{
+		NamePos: pos,
+		Name:    typeName,
+	}
+}
+
+// makeASTRecordType parses a C record (struct or union) and translates it into
+// a Go struct type.
+func (p *cgoPackage) makeASTRecordType(cursor C.GoCXCursor, pos token.Pos) *elaboratedTypeInfo {
+	fieldList := &ast.FieldList{
+		Opening: pos,
+		Closing: pos,
+	}
+	var bitfieldList []bitfieldInfo
+	inBitfield := false
+	bitfieldNum := 0
+	ref := storedRefs.Put(struct {
+		fieldList    *ast.FieldList
+		pkg          *cgoPackage
+		inBitfield   *bool
+		bitfieldNum  *int
+		bitfieldList *[]bitfieldInfo
+	}{fieldList, p, &inBitfield, &bitfieldNum, &bitfieldList})
+	defer storedRefs.Remove(ref)
+	C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_struct_visitor), C.CXClientData(ref))
+	renameFieldKeywords(fieldList)
+	switch C.tinygo_clang_getCursorKind(cursor) {
+	case C.CXCursor_StructDecl:
+		return &elaboratedTypeInfo{
+			typeExpr: &ast.StructType{
+				Struct: pos,
+				Fields: fieldList,
+			},
+			pos:       pos,
+			bitfields: bitfieldList,
+		}
+	case C.CXCursor_UnionDecl:
+		typeInfo := &elaboratedTypeInfo{
+			typeExpr: &ast.StructType{
+				Struct: pos,
+				Fields: fieldList,
+			},
+			pos:       pos,
+			bitfields: bitfieldList,
+		}
+		if len(fieldList.List) <= 1 {
+			// Useless union, treat it as a regular struct.
+			return typeInfo
+		}
+		if bitfieldList != nil {
+			// This is valid C... but please don't do this.
+			p.addError(pos, "bitfield in a union is not supported")
+		}
+		typ := C.tinygo_clang_getCursorType(cursor)
+		alignInBytes := int64(C.clang_Type_getAlignOf(typ))
+		sizeInBytes := int64(C.clang_Type_getSizeOf(typ))
+		if sizeInBytes == 0 {
+			p.addError(pos, "zero-length union is not supported")
+		}
+		typeInfo.unionSize = sizeInBytes
+		typeInfo.unionAlign = alignInBytes
+		return typeInfo
+	default:
+		cursorKind := C.tinygo_clang_getCursorKind(cursor)
+		cursorKindSpelling := getString(C.clang_getCursorKindSpelling(cursorKind))
+		p.addError(pos, fmt.Sprintf("expected StructDecl or UnionDecl, not %s", cursorKindSpelling))
+		return &elaboratedTypeInfo{
+			typeExpr: &ast.StructType{
+				Struct: pos,
+			},
+			pos: pos,
+		}
+	}
+}
+
+//export tinygo_clang_struct_visitor
+func tinygo_clang_struct_visitor(c, parent C.GoCXCursor, client_data C.CXClientData) C.int {
+	passed := storedRefs.Get(unsafe.Pointer(client_data)).(struct {
+		fieldList    *ast.FieldList
+		pkg          *cgoPackage
+		inBitfield   *bool
+		bitfieldNum  *int
+		bitfieldList *[]bitfieldInfo
+	})
+	fieldList := passed.fieldList
+	p := passed.pkg
+	inBitfield := passed.inBitfield
+	bitfieldNum := passed.bitfieldNum
+	bitfieldList := passed.bitfieldList
+	pos := p.getCursorPosition(c)
+	switch cursorKind := C.tinygo_clang_getCursorKind(c); cursorKind {
+	case C.CXCursor_FieldDecl:
+		// Expected. This is a regular field.
+	case C.CXCursor_StructDecl, C.CXCursor_UnionDecl:
+		// Ignore. The next field will be the struct/union itself.
+		return C.CXChildVisit_Continue
+	default:
+		cursorKindSpelling := getString(C.clang_getCursorKindSpelling(cursorKind))
+		p.addError(pos, fmt.Sprintf("expected FieldDecl in struct or union, not %s", cursorKindSpelling))
+		return C.CXChildVisit_Continue
+	}
+	name := getString(C.tinygo_clang_getCursorSpelling(c))
+	if name == "" {
+		// Assume this is a bitfield of 0 bits.
+		// Warning: this is not necessarily true!
+		return C.CXChildVisit_Continue
+	}
+	typ := C.tinygo_clang_getCursorType(c)
+	field := &ast.Field{
+		Type: p.makeASTType(typ, p.getCursorPosition(c)),
+	}
+	offsetof := int64(C.clang_Type_getOffsetOf(C.tinygo_clang_getCursorType(parent), C.CString(name)))
+	alignOf := int64(C.clang_Type_getAlignOf(typ) * 8)
+	bitfieldOffset := offsetof % alignOf
+	if bitfieldOffset != 0 {
+		if C.tinygo_clang_Cursor_isBitField(c) != 1 {
+			p.addError(pos, "expected a bitfield")
+			return C.CXChildVisit_Continue
+		}
+		if !*inBitfield {
+			*bitfieldNum++
+		}
+		bitfieldName := "__bitfield_" + strconv.Itoa(*bitfieldNum)
+		prevField := fieldList.List[len(fieldList.List)-1]
+		if !*inBitfield {
+			// The previous element also was a bitfield, but wasn't noticed
+			// then. Add it now.
+			*inBitfield = true
+			*bitfieldList = append(*bitfieldList, bitfieldInfo{
+				field:    prevField,
+				name:     prevField.Names[0].Name,
+				startBit: 0,
+				pos:      prevField.Names[0].NamePos,
+			})
+			prevField.Names[0].Name = bitfieldName
+			prevField.Names[0].Obj.Name = bitfieldName
+		}
+		prevBitfield := &(*bitfieldList)[len(*bitfieldList)-1]
+		prevBitfield.endBit = bitfieldOffset
+		*bitfieldList = append(*bitfieldList, bitfieldInfo{
+			field:    prevField,
+			name:     name,
+			startBit: bitfieldOffset,
+			pos:      pos,
+		})
+		return C.CXChildVisit_Continue
+	}
+	*inBitfield = false
+	field.Names = []*ast.Ident{
+		&ast.Ident{
+			NamePos: pos,
+			Name:    name,
+			Obj: &ast.Object{
+				Kind: ast.Var,
+				Name: name,
+				Decl: field,
+			},
+		},
+	}
+	fieldList.List = append(fieldList.List, field)
+	return C.CXChildVisit_Continue
+}
+
+//export tinygo_clang_enum_visitor
+func tinygo_clang_enum_visitor(c, parent C.GoCXCursor, client_data C.CXClientData) C.int {
+	p := storedRefs.Get(unsafe.Pointer(client_data)).(*cgoPackage)
+	name := getString(C.tinygo_clang_getCursorSpelling(c))
+	pos := p.getCursorPosition(c)
+	value := C.tinygo_clang_getEnumConstantDeclValue(c)
+	p.constants[name] = constantInfo{
+		expr: &ast.BasicLit{pos, token.INT, strconv.FormatInt(int64(value), 10)},
+		pos:  pos,
+	}
+	return C.CXChildVisit_Continue
+}
+
+//export tinygo_clang_inclusion_visitor
+func tinygo_clang_inclusion_visitor(includedFile C.CXFile, inclusionStack *C.CXSourceLocation, includeLen C.unsigned, clientData C.CXClientData) {
+	callback := storedRefs.Get(unsafe.Pointer(clientData)).(func(C.CXFile))
+	callback(includedFile)
+}

cgo/libclang_config.go

@@ -0,0 +1,14 @@
+// +build !byollvm
+// +build !llvm10
+
+package cgo
+
+/*
+#cgo linux   CFLAGS:  -I/usr/lib/llvm-11/include
+#cgo darwin  CFLAGS:  -I/usr/local/opt/llvm@11/include
+#cgo freebsd CFLAGS:  -I/usr/local/llvm11/include
+#cgo linux   LDFLAGS: -L/usr/lib/llvm-11/lib -lclang
+#cgo darwin  LDFLAGS: -L/usr/local/opt/llvm@11/lib -lclang -lffi
+#cgo freebsd LDFLAGS: -L/usr/local/llvm11/lib -lclang
+*/
+import "C"

cgo/libclang_config_llvm10.go

@@ -0,0 +1,14 @@
+// +build !byollvm
+// +build llvm10
+
+package cgo
+
+/*
+#cgo linux  CFLAGS: -I/usr/lib/llvm-10/include
+#cgo darwin CFLAGS: -I/usr/local/opt/llvm@10/include
+#cgo freebsd CFLAGS: -I/usr/local/llvm10/include
+#cgo linux  LDFLAGS: -L/usr/lib/llvm-10/lib -lclang
+#cgo darwin LDFLAGS: -L/usr/local/opt/llvm@10/lib -lclang -lffi
+#cgo freebsd LDFLAGS: -L/usr/local/llvm10/lib -lclang
+*/
+import "C"

cgo/libclang_stubs.c

@@ -0,0 +1,70 @@
+
+// This file implements some small trampoline functions. The signatures
+// are slightly different from the ones defined in libclang.go, but they
+// should be ABI compatible.
+
+#include <clang-c/Index.h> // if this fails, install libclang-10-dev
+
+CXCursor tinygo_clang_getTranslationUnitCursor(CXTranslationUnit tu) {
+	return clang_getTranslationUnitCursor(tu);
+}
+
+unsigned tinygo_clang_visitChildren(CXCursor parent, CXCursorVisitor visitor, CXClientData client_data) {
+	return clang_visitChildren(parent, visitor, client_data);
+}
+
+CXString tinygo_clang_getCursorSpelling(CXCursor c) {
+	return clang_getCursorSpelling(c);
+}
+
+enum CXCursorKind tinygo_clang_getCursorKind(CXCursor c) {
+	return clang_getCursorKind(c);
+}
+
+CXType tinygo_clang_getCursorType(CXCursor c) {
+	return clang_getCursorType(c);
+}
+
+CXCursor tinygo_clang_getTypeDeclaration(CXType t) {
+	return clang_getTypeDeclaration(t);
+}
+
+CXType tinygo_clang_getTypedefDeclUnderlyingType(CXCursor c) {
+	return clang_getTypedefDeclUnderlyingType(c);
+}
+
+CXType tinygo_clang_getCursorResultType(CXCursor c) {
+	return clang_getCursorResultType(c);
+}
+
+int tinygo_clang_Cursor_getNumArguments(CXCursor c) {
+	return clang_Cursor_getNumArguments(c);
+}
+
+CXCursor tinygo_clang_Cursor_getArgument(CXCursor c, unsigned i) {
+	return clang_Cursor_getArgument(c, i);
+}
+
+CXSourceLocation tinygo_clang_getCursorLocation(CXCursor c) {
+	return clang_getCursorLocation(c);
+}
+
+CXSourceRange tinygo_clang_getCursorExtent(CXCursor c) {
+	return clang_getCursorExtent(c);
+}
+
+CXTranslationUnit tinygo_clang_Cursor_getTranslationUnit(CXCursor c) {
+	return clang_Cursor_getTranslationUnit(c);
+}
+
+long long tinygo_clang_getEnumConstantDeclValue(CXCursor c) {
+	return clang_getEnumConstantDeclValue(c);
+}
+
+CXType tinygo_clang_getEnumDeclIntegerType(CXCursor c) {
+	return clang_getEnumDeclIntegerType(c);
+}
+
+unsigned tinygo_clang_Cursor_isBitField(CXCursor c) {
+	return clang_Cursor_isBitField(c);
+}

cgo/security.go

@@ -0,0 +1,301 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file has been copied from the Go 1.13 release tree.
+
+// Checking of compiler and linker flags.
+// We must avoid flags like -fplugin=, which can allow
+// arbitrary code execution during the build.
+// Do not make changes here without carefully
+// considering the implications.
+// (That's why the code is isolated in a file named security.go.)
+//
+// Note that -Wl,foo means split foo on commas and pass to
+// the linker, so that -Wl,-foo,bar means pass -foo bar to
+// the linker. Similarly -Wa,foo for the assembler and so on.
+// If any of these are permitted, the wildcard portion must
+// disallow commas.
+//
+// Note also that GNU binutils accept any argument @foo
+// as meaning "read more flags from the file foo", so we must
+// guard against any command-line argument beginning with @,
+// even things like "-I @foo".
+// We use safeArg (which is even more conservative)
+// to reject these.
+//
+// Even worse, gcc -I@foo (one arg) turns into cc1 -I @foo (two args),
+// so although gcc doesn't expand the @foo, cc1 will.
+// So out of paranoia, we reject @ at the beginning of every
+// flag argument that might be split into its own argument.
+
+package cgo
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+)
+
+var re = regexp.MustCompile
+
+var validCompilerFlags = []*regexp.Regexp{
+	re(`-D([A-Za-z_].*)`),
+	re(`-F([^@\-].*)`),
+	re(`-I([^@\-].*)`),
+	re(`-O`),
+	re(`-O([^@\-].*)`),
+	re(`-W`),
+	re(`-W([^@,]+)`), // -Wall but not -Wa,-foo.
+	re(`-Wa,-mbig-obj`),
+	re(`-Wp,-D([A-Za-z_].*)`),
+	re(`-ansi`),
+	re(`-f(no-)?asynchronous-unwind-tables`),
+	re(`-f(no-)?blocks`),
+	re(`-f(no-)builtin-[a-zA-Z0-9_]*`),
+	re(`-f(no-)?common`),
+	re(`-f(no-)?constant-cfstrings`),
+	re(`-fdiagnostics-show-note-include-stack`),
+	re(`-f(no-)?eliminate-unused-debug-types`),
+	re(`-f(no-)?exceptions`),
+	re(`-f(no-)?fast-math`),
+	re(`-f(no-)?inline-functions`),
+	re(`-finput-charset=([^@\-].*)`),
+	re(`-f(no-)?fat-lto-objects`),
+	re(`-f(no-)?keep-inline-dllexport`),
+	re(`-f(no-)?lto`),
+	re(`-fmacro-backtrace-limit=(.+)`),
+	re(`-fmessage-length=(.+)`),
+	re(`-f(no-)?modules`),
+	re(`-f(no-)?objc-arc`),
+	re(`-f(no-)?objc-nonfragile-abi`),
+	re(`-f(no-)?objc-legacy-dispatch`),
+	re(`-f(no-)?omit-frame-pointer`),
+	re(`-f(no-)?openmp(-simd)?`),
+	re(`-f(no-)?permissive`),
+	re(`-f(no-)?(pic|PIC|pie|PIE)`),
+	re(`-f(no-)?plt`),
+	re(`-f(no-)?rtti`),
+	re(`-f(no-)?split-stack`),
+	re(`-f(no-)?stack-(.+)`),
+	re(`-f(no-)?strict-aliasing`),
+	re(`-f(un)signed-char`),
+	re(`-f(no-)?use-linker-plugin`), // safe if -B is not used; we don't permit -B
+	re(`-f(no-)?visibility-inlines-hidden`),
+	re(`-fsanitize=(.+)`),
+	re(`-ftemplate-depth-(.+)`),
+	re(`-fvisibility=(.+)`),
+	re(`-g([^@\-].*)?`),
+	re(`-m32`),
+	re(`-m64`),
+	re(`-m(abi|arch|cpu|fpu|tune)=([^@\-].*)`),
+	re(`-m(no-)?v?aes`),
+	re(`-marm`),
+	re(`-m(no-)?avx[0-9a-z]*`),
+	re(`-mfloat-abi=([^@\-].*)`),
+	re(`-mfpmath=[0-9a-z,+]*`),
+	re(`-m(no-)?avx[0-9a-z.]*`),
+	re(`-m(no-)?ms-bitfields`),
+	re(`-m(no-)?stack-(.+)`),
+	re(`-mmacosx-(.+)`),
+	re(`-mios-simulator-version-min=(.+)`),
+	re(`-miphoneos-version-min=(.+)`),
+	re(`-mtvos-simulator-version-min=(.+)`),
+	re(`-mtvos-version-min=(.+)`),
+	re(`-mwatchos-simulator-version-min=(.+)`),
+	re(`-mwatchos-version-min=(.+)`),
+	re(`-mnop-fun-dllimport`),
+	re(`-m(no-)?sse[0-9.]*`),
+	re(`-m(no-)?ssse3`),
+	re(`-mthumb(-interwork)?`),
+	re(`-mthreads`),
+	re(`-mwindows`),
+	re(`--param=ssp-buffer-size=[0-9]*`),
+	re(`-pedantic(-errors)?`),
+	re(`-pipe`),
+	re(`-pthread`),
+	re(`-?-std=([^@\-].*)`),
+	re(`-?-stdlib=([^@\-].*)`),
+	re(`--sysroot=([^@\-].*)`),
+	re(`-w`),
+	re(`-x([^@\-].*)`),
+	re(`-v`),
+}
+
+var validCompilerFlagsWithNextArg = []string{
+	"-arch",
+	"-D",
+	"-I",
+	"-framework",
+	"-isysroot",
+	"-isystem",
+	"--sysroot",
+	"-target",
+	"-x",
+}
+
+var validLinkerFlags = []*regexp.Regexp{
+	re(`-F([^@\-].*)`),
+	re(`-l([^@\-].*)`),
+	re(`-L([^@\-].*)`),
+	re(`-O`),
+	re(`-O([^@\-].*)`),
+	re(`-f(no-)?(pic|PIC|pie|PIE)`),
+	re(`-f(no-)?openmp(-simd)?`),
+	re(`-fsanitize=([^@\-].*)`),
+	re(`-flat_namespace`),
+	re(`-g([^@\-].*)?`),
+	re(`-headerpad_max_install_names`),
+	re(`-m(abi|arch|cpu|fpu|tune)=([^@\-].*)`),
+	re(`-mfloat-abi=([^@\-].*)`),
+	re(`-mmacosx-(.+)`),
+	re(`-mios-simulator-version-min=(.+)`),
+	re(`-miphoneos-version-min=(.+)`),
+	re(`-mthreads`),
+	re(`-mwindows`),
+	re(`-(pic|PIC|pie|PIE)`),
+	re(`-pthread`),
+	re(`-rdynamic`),
+	re(`-shared`),
+	re(`-?-static([-a-z0-9+]*)`),
+	re(`-?-stdlib=([^@\-].*)`),
+	re(`-v`),
+
+	// Note that any wildcards in -Wl need to exclude comma,
+	// since -Wl splits its argument at commas and passes
+	// them all to the linker uninterpreted. Allowing comma
+	// in a wildcard would allow tunnelling arbitrary additional
+	// linker arguments through one of these.
+	re(`-Wl,--(no-)?allow-multiple-definition`),
+	re(`-Wl,--(no-)?allow-shlib-undefined`),
+	re(`-Wl,--(no-)?as-needed`),
+	re(`-Wl,-Bdynamic`),
+	re(`-Wl,-berok`),
+	re(`-Wl,-Bstatic`),
+	re(`-WL,-O([^@,\-][^,]*)?`),
+	re(`-Wl,-d[ny]`),
+	re(`-Wl,--disable-new-dtags`),
+	re(`-Wl,-e[=,][a-zA-Z0-9]*`),
+	re(`-Wl,--enable-new-dtags`),
+	re(`-Wl,--end-group`),
+	re(`-Wl,--(no-)?export-dynamic`),
+	re(`-Wl,-framework,[^,@\-][^,]+`),
+	re(`-Wl,-headerpad_max_install_names`),
+	re(`-Wl,--no-undefined`),
+	re(`-Wl,-R([^@\-][^,@]*$)`),
+	re(`-Wl,--just-symbols[=,]([^,@\-][^,@]+)`),
+	re(`-Wl,-rpath(-link)?[=,]([^,@\-][^,]+)`),
+	re(`-Wl,-s`),
+	re(`-Wl,-search_paths_first`),
+	re(`-Wl,-sectcreate,([^,@\-][^,]+),([^,@\-][^,]+),([^,@\-][^,]+)`),
+	re(`-Wl,--start-group`),
+	re(`-Wl,-?-static`),
+	re(`-Wl,-?-subsystem,(native|windows|console|posix|xbox)`),
+	re(`-Wl,-syslibroot[=,]([^,@\-][^,]+)`),
+	re(`-Wl,-undefined[=,]([^,@\-][^,]+)`),
+	re(`-Wl,-?-unresolved-symbols=[^,]+`),
+	re(`-Wl,--(no-)?warn-([^,]+)`),
+	re(`-Wl,-z,(no)?execstack`),
+	re(`-Wl,-z,relro`),
+
+	re(`[a-zA-Z0-9_/].*\.(a|o|obj|dll|dylib|so)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
+	re(`\./.*\.(a|o|obj|dll|dylib|so)`),
+}
+
+var validLinkerFlagsWithNextArg = []string{
+	"-arch",
+	"-F",
+	"-l",
+	"-L",
+	"-framework",
+	"-isysroot",
+	"--sysroot",
+	"-target",
+	"-Wl,-framework",
+	"-Wl,-rpath",
+	"-Wl,-R",
+	"-Wl,--just-symbols",
+	"-Wl,-undefined",
+}
+
+func checkCompilerFlags(name string, list []string) error {
+	return checkFlags(name, list, validCompilerFlags, validCompilerFlagsWithNextArg)
+}
+
+func checkLinkerFlags(name string, list []string) error {
+	return checkFlags(name, list, validLinkerFlags, validLinkerFlagsWithNextArg)
+}
+
+func checkFlags(name string, list []string, valid []*regexp.Regexp, validNext []string) error {
+	// Let users override rules with $CGO_CFLAGS_ALLOW, $CGO_CFLAGS_DISALLOW, etc.
+	var (
+		allow    *regexp.Regexp
+		disallow *regexp.Regexp
+	)
+	if env := os.Getenv("CGO_" + name + "_ALLOW"); env != "" {
+		r, err := regexp.Compile(env)
+		if err != nil {
+			return fmt.Errorf("parsing $CGO_%s_ALLOW: %v", name, err)
+		}
+		allow = r
+	}
+	if env := os.Getenv("CGO_" + name + "_DISALLOW"); env != "" {
+		r, err := regexp.Compile(env)
+		if err != nil {
+			return fmt.Errorf("parsing $CGO_%s_DISALLOW: %v", name, err)
+		}
+		disallow = r
+	}
+
+Args:
+	for i := 0; i < len(list); i++ {
+		arg := list[i]
+		if disallow != nil && disallow.FindString(arg) == arg {
+			goto Bad
+		}
+		if allow != nil && allow.FindString(arg) == arg {
+			continue Args
+		}
+		for _, re := range valid {
+			if re.FindString(arg) == arg { // must be complete match
+				continue Args
+			}
+		}
+		for _, x := range validNext {
+			if arg == x {
+				if i+1 < len(list) && safeArg(list[i+1]) {
+					i++
+					continue Args
+				}
+
+				// Permit -Wl,-framework -Wl,name.
+				if i+1 < len(list) &&
+					strings.HasPrefix(arg, "-Wl,") &&
+					strings.HasPrefix(list[i+1], "-Wl,") &&
+					safeArg(list[i+1][4:]) &&
+					!strings.Contains(list[i+1][4:], ",") {
+					i++
+					continue Args
+				}
+
+				if i+1 < len(list) {
+					return fmt.Errorf("invalid flag: %s %s (see https://golang.org/s/invalidflag)", arg, list[i+1])
+				}
+				return fmt.Errorf("invalid flag: %s without argument (see https://golang.org/s/invalidflag)", arg)
+			}
+		}
+	Bad:
+		return fmt.Errorf("invalid flag: %s", arg)
+	}
+	return nil
+}
+
+func safeArg(name string) bool {
+	if name == "" {
+		return false
+	}
+	c := name[0]
+	return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '.' || c == '_' || c == '/' || c >= utf8.RuneSelf
+}

cgo/security_test.go

@@ -0,0 +1,260 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file has been copied from the Go 1.13 release tree.
+
+package cgo
+
+import (
+	"os"
+	"testing"
+)
+
+var goodCompilerFlags = [][]string{
+	{"-DFOO"},
+	{"-Dfoo=bar"},
+	{"-F/Qt"},
+	{"-I/"},
+	{"-I/etc/passwd"},
+	{"-I."},
+	{"-O"},
+	{"-O2"},
+	{"-Osmall"},
+	{"-W"},
+	{"-Wall"},
+	{"-fobjc-arc"},
+	{"-fno-objc-arc"},
+	{"-fomit-frame-pointer"},
+	{"-fno-omit-frame-pointer"},
+	{"-fpic"},
+	{"-fno-pic"},
+	{"-fPIC"},
+	{"-fno-PIC"},
+	{"-fpie"},
+	{"-fno-pie"},
+	{"-fPIE"},
+	{"-fno-PIE"},
+	{"-fsplit-stack"},
+	{"-fno-split-stack"},
+	{"-fstack-xxx"},
+	{"-fno-stack-xxx"},
+	{"-fsanitize=hands"},
+	{"-g"},
+	{"-ggdb"},
+	{"-march=souza"},
+	{"-mcpu=123"},
+	{"-mfpu=123"},
+	{"-mtune=happybirthday"},
+	{"-mstack-overflow"},
+	{"-mno-stack-overflow"},
+	{"-mmacosx-version"},
+	{"-mnop-fun-dllimport"},
+	{"-pthread"},
+	{"-std=c99"},
+	{"-xc"},
+	{"-D", "FOO"},
+	{"-D", "foo=bar"},
+	{"-I", "."},
+	{"-I", "/etc/passwd"},
+	{"-I", "世界"},
+	{"-framework", "Chocolate"},
+	{"-x", "c"},
+	{"-v"},
+}
+
+var badCompilerFlags = [][]string{
+	{"-D@X"},
+	{"-D-X"},
+	{"-F@dir"},
+	{"-F-dir"},
+	{"-I@dir"},
+	{"-I-dir"},
+	{"-O@1"},
+	{"-Wa,-foo"},
+	{"-W@foo"},
+	{"-g@gdb"},
+	{"-g-gdb"},
+	{"-march=@dawn"},
+	{"-march=-dawn"},
+	{"-std=@c99"},
+	{"-std=-c99"},
+	{"-x@c"},
+	{"-x-c"},
+	{"-D", "@foo"},
+	{"-D", "-foo"},
+	{"-I", "@foo"},
+	{"-I", "-foo"},
+	{"-framework", "-Caffeine"},
+	{"-framework", "@Home"},
+	{"-x", "--c"},
+	{"-x", "@obj"},
+}
+
+func TestCheckCompilerFlags(t *testing.T) {
+	for _, f := range goodCompilerFlags {
+		if err := checkCompilerFlags("test", f); err != nil {
+			t.Errorf("unexpected error for %q: %v", f, err)
+		}
+	}
+	for _, f := range badCompilerFlags {
+		if err := checkCompilerFlags("test", f); err == nil {
+			t.Errorf("missing error for %q", f)
+		}
+	}
+}
+
+var goodLinkerFlags = [][]string{
+	{"-Fbar"},
+	{"-lbar"},
+	{"-Lbar"},
+	{"-fpic"},
+	{"-fno-pic"},
+	{"-fPIC"},
+	{"-fno-PIC"},
+	{"-fpie"},
+	{"-fno-pie"},
+	{"-fPIE"},
+	{"-fno-PIE"},
+	{"-fsanitize=hands"},
+	{"-g"},
+	{"-ggdb"},
+	{"-march=souza"},
+	{"-mcpu=123"},
+	{"-mfpu=123"},
+	{"-mtune=happybirthday"},
+	{"-pic"},
+	{"-pthread"},
+	{"-Wl,-rpath,foo"},
+	{"-Wl,-rpath,$ORIGIN/foo"},
+	{"-Wl,-R", "/foo"},
+	{"-Wl,-R", "foo"},
+	{"-Wl,-R,foo"},
+	{"-Wl,--just-symbols=foo"},
+	{"-Wl,--just-symbols,foo"},
+	{"-Wl,--warn-error"},
+	{"-Wl,--no-warn-error"},
+	{"foo.so"},
+	{"_世界.dll"},
+	{"./x.o"},
+	{"libcgosotest.dylib"},
+	{"-F", "framework"},
+	{"-l", "."},
+	{"-l", "/etc/passwd"},
+	{"-l", "世界"},
+	{"-L", "framework"},
+	{"-framework", "Chocolate"},
+	{"-v"},
+	{"-Wl,-framework", "-Wl,Chocolate"},
+	{"-Wl,-framework,Chocolate"},
+	{"-Wl,-unresolved-symbols=ignore-all"},
+}
+
+var badLinkerFlags = [][]string{
+	{"-DFOO"},
+	{"-Dfoo=bar"},
+	{"-W"},
+	{"-Wall"},
+	{"-fobjc-arc"},
+	{"-fno-objc-arc"},
+	{"-fomit-frame-pointer"},
+	{"-fno-omit-frame-pointer"},
+	{"-fsplit-stack"},
+	{"-fno-split-stack"},
+	{"-fstack-xxx"},
+	{"-fno-stack-xxx"},
+	{"-mstack-overflow"},
+	{"-mno-stack-overflow"},
+	{"-mnop-fun-dllimport"},
+	{"-std=c99"},
+	{"-xc"},
+	{"-D", "FOO"},
+	{"-D", "foo=bar"},
+	{"-I", "FOO"},
+	{"-L", "@foo"},
+	{"-L", "-foo"},
+	{"-x", "c"},
+	{"-D@X"},
+	{"-D-X"},
+	{"-I@dir"},
+	{"-I-dir"},
+	{"-O@1"},
+	{"-Wa,-foo"},
+	{"-W@foo"},
+	{"-g@gdb"},
+	{"-g-gdb"},
+	{"-march=@dawn"},
+	{"-march=-dawn"},
+	{"-std=@c99"},
+	{"-std=-c99"},
+	{"-x@c"},
+	{"-x-c"},
+	{"-D", "@foo"},
+	{"-D", "-foo"},
+	{"-I", "@foo"},
+	{"-I", "-foo"},
+	{"-l", "@foo"},
+	{"-l", "-foo"},
+	{"-framework", "-Caffeine"},
+	{"-framework", "@Home"},
+	{"-Wl,-framework,-Caffeine"},
+	{"-Wl,-framework", "-Wl,@Home"},
+	{"-Wl,-framework", "@Home"},
+	{"-Wl,-framework,Chocolate,@Home"},
+	{"-x", "--c"},
+	{"-x", "@obj"},
+	{"-Wl,-rpath,@foo"},
+	{"-Wl,-R,foo,bar"},
+	{"-Wl,-R,@foo"},
+	{"-Wl,--just-symbols,@foo"},
+	{"../x.o"},
+}
+
+func TestCheckLinkerFlags(t *testing.T) {
+	for _, f := range goodLinkerFlags {
+		if err := checkLinkerFlags("test", f); err != nil {
+			t.Errorf("unexpected error for %q: %v", f, err)
+		}
+	}
+	for _, f := range badLinkerFlags {
+		if err := checkLinkerFlags("test", f); err == nil {
+			t.Errorf("missing error for %q", f)
+		}
+	}
+}
+
+func TestCheckFlagAllowDisallow(t *testing.T) {
+	if err := checkCompilerFlags("TEST", []string{"-disallow"}); err == nil {
+		t.Fatalf("missing error for -disallow")
+	}
+	os.Setenv("CGO_TEST_ALLOW", "-disallo")
+	if err := checkCompilerFlags("TEST", []string{"-disallow"}); err == nil {
+		t.Fatalf("missing error for -disallow with CGO_TEST_ALLOW=-disallo")
+	}
+	os.Setenv("CGO_TEST_ALLOW", "-disallow")
+	if err := checkCompilerFlags("TEST", []string{"-disallow"}); err != nil {
+		t.Fatalf("unexpected error for -disallow with CGO_TEST_ALLOW=-disallow: %v", err)
+	}
+	os.Unsetenv("CGO_TEST_ALLOW")
+
+	if err := checkCompilerFlags("TEST", []string{"-Wall"}); err != nil {
+		t.Fatalf("unexpected error for -Wall: %v", err)
+	}
+	os.Setenv("CGO_TEST_DISALLOW", "-Wall")
+	if err := checkCompilerFlags("TEST", []string{"-Wall"}); err == nil {
+		t.Fatalf("missing error for -Wall with CGO_TEST_DISALLOW=-Wall")
+	}
+	os.Setenv("CGO_TEST_ALLOW", "-Wall") // disallow wins
+	if err := checkCompilerFlags("TEST", []string{"-Wall"}); err == nil {
+		t.Fatalf("missing error for -Wall with CGO_TEST_DISALLOW=-Wall and CGO_TEST_ALLOW=-Wall")
+	}
+
+	os.Setenv("CGO_TEST_ALLOW", "-fplugin.*")
+	os.Setenv("CGO_TEST_DISALLOW", "-fplugin=lint.so")
+	if err := checkCompilerFlags("TEST", []string{"-fplugin=faster.so"}); err != nil {
+		t.Fatalf("unexpected error for -fplugin=faster.so: %v", err)
+	}
+	if err := checkCompilerFlags("TEST", []string{"-fplugin=lint.so"}); err == nil {
+		t.Fatalf("missing error for -fplugin=lint.so: %v", err)
+	}
+}

cgo/sync.go

@@ -0,0 +1,46 @@
+package cgo
+
+import (
+	"sync"
+	"unsafe"
+)
+
+// #include <stdlib.h>
+import "C"
+
+// refMap is a convenient way to store opaque references that can be passed to
+// C. It is useful if an API uses function pointers and you cannot pass a Go
+// pointer but only a C pointer.
+type refMap struct {
+	refs map[unsafe.Pointer]interface{}
+	lock sync.Mutex
+}
+
+// Put stores a value in the map. It can later be retrieved using Get. It must
+// be removed using Remove to avoid memory leaks.
+func (m *refMap) Put(v interface{}) unsafe.Pointer {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	if m.refs == nil {
+		m.refs = make(map[unsafe.Pointer]interface{}, 1)
+	}
+	ref := C.malloc(1)
+	m.refs[ref] = v
+	return ref
+}
+
+// Get returns a stored value previously inserted with Put. Use the same
+// reference as you got from Put.
+func (m *refMap) Get(ref unsafe.Pointer) interface{} {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	return m.refs[ref]
+}
+
+// Remove deletes a single reference from the map.
+func (m *refMap) Remove(ref unsafe.Pointer) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	delete(m.refs, ref)
+	C.free(ref)
+}

cgo/testdata/basic.go

@@ -0,0 +1,3 @@
+package main
+
+import "C"

cgo/testdata/basic.out.go

@@ -0,0 +1,26 @@
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16

cgo/testdata/const.go

@@ -0,0 +1,12 @@
+package main
+
+/*
+#define foo 3
+#define bar foo
+*/
+import "C"
+
+const (
+	Foo = C.foo
+	Bar = C.bar
+)

cgo/testdata/const.out.go

@@ -0,0 +1,29 @@
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.bar = C.foo
+const C.foo = 3
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16

cgo/testdata/errors.go

@@ -0,0 +1,33 @@
+package main
+
+/*
+#warning some warning
+
+typedef struct {
+	int x;
+	int y;
+} point_t;
+
+typedef someType noType; // undefined type
+
+#define SOME_CONST_1 5) // invalid const syntax
+#define SOME_CONST_2 6) // const not used (so no error)
+#define SOME_CONST_3 1234 // const too large for byte
+*/
+import "C"
+
+// Make sure that errors for the following lines won't change with future
+// additions to the CGo preamble.
+//line errors.go:100
+var (
+	// constant too large
+	_ C.uint8_t = 2 << 10
+
+	// z member does not exist
+	_ C.point_t = C.point_t{z: 3}
+
+	// constant has syntax error
+	_ = C.SOME_CONST_1
+
+	_ byte = C.SOME_CONST_3
+)

cgo/testdata/errors.out.go

@@ -0,0 +1,43 @@
+// CGo errors:
+//     testdata/errors.go:4:2: warning: some warning
+//     testdata/errors.go:11:9: error: unknown type name 'someType'
+//     testdata/errors.go:13:23: unexpected token )
+
+// Type checking errors after CGo processing:
+//     testdata/errors.go:102: cannot use 2 << 10 (untyped int constant 2048) as uint8 value in variable declaration (overflows)
+//     testdata/errors.go:105: unknown field z in struct literal
+//     testdata/errors.go:108: undeclared name: C.SOME_CONST_1
+//     testdata/errors.go:110: cannot use C.SOME_CONST_3 (untyped int constant 1234) as byte value in variable declaration (overflows)
+
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.SOME_CONST_3 = 1234
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16
+type C.point_t = struct {
+	x C.int
+	y C.int
+}

cgo/testdata/flags.go

@@ -0,0 +1,37 @@
+package main
+
+/*
+// this name doesn't exist
+#cgo  NOFLAGS: -foo
+
+// unknown flag
+#cgo CFLAGS: -fdoes-not-exist -DNOTDEFINED
+
+#cgo CFLAGS: -DFOO
+
+#cgo CFLAGS: -Iinclude
+#include "foo.h"
+
+#if defined(FOO)
+#define BAR 3
+#else
+#define BAR 5
+#endif
+
+#if defined(NOTDEFINED)
+#warning flag must not be defined
+#endif
+
+// Check Compiler flags
+#cgo LDFLAGS: -lc
+
+// This flag is not valid ldflags
+#cgo LDFLAGS: -does-not-exists
+
+*/
+import "C"
+
+var (
+	_ = C.BAR
+	_ = C.FOO_H
+)

cgo/testdata/flags.out.go

@@ -0,0 +1,34 @@
+// CGo errors:
+//     testdata/flags.go:5:7: invalid #cgo line: NOFLAGS
+//     testdata/flags.go:8:13: invalid flag: -fdoes-not-exist
+//     testdata/flags.go:29:14: invalid flag: -does-not-exists
+
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.BAR = 3
+const C.FOO_H = 1
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16

cgo/testdata/include/foo.h

@@ -0,0 +1 @@
+#define FOO_H 1

cgo/testdata/types.go

@@ -0,0 +1,175 @@
+package main
+
+/*
+// Simple typedef.
+typedef int myint;
+
+// Structs, with or without name.
+typedef struct {
+	int x;
+	int y;
+} point2d_t;
+typedef struct point3d {
+	int x;
+	int y;
+	int z;
+} point3d_t;
+
+// Structs with reserved field names.
+struct type1 {
+	// All these fields should be renamed.
+	int type;
+	int _type;
+	int __type;
+};
+struct type2 {
+	// This field should not be renamed.
+	int _type;
+};
+
+// Unions.
+typedef union {
+	// Union should be treated as a struct.
+	int i;
+} union1_t;
+typedef union {
+	// Union must contain a single field and have special getters/setters.
+	int    i;
+	double d;
+	short  s;
+} union3_t;
+typedef union union2d {
+	int i;
+	double d[2];
+} union2d_t;
+typedef union {
+	unsigned char arr[10];
+} unionarray_t;
+
+// Nested structs and unions.
+typedef struct {
+	point2d_t begin;
+	point2d_t end;
+	int       tag;
+	union {
+		point2d_t area;
+		point3d_t solid;
+	} coord;
+} struct_nested_t;
+typedef union {
+	point3d_t    point;
+	unionarray_t array;
+	union3_t     thing;
+} union_nested_t;
+
+// Enums. These define constant numbers. All these constants must be given the
+// correct number.
+typedef enum option {
+	optionA,
+	optionB,
+	optionC = -5,
+	optionD,
+	optionE = 10,
+	optionF,
+	optionG,
+} option_t;
+enum unused {
+	unused1 = 5,
+};
+
+// Anonymous enum.
+typedef enum {
+	option2A = 20,
+} option2_t;
+
+// Various types that are usually translated directly to Go types, but storing
+// them in a struct reveals them.
+typedef struct {
+	float  f;
+	double d;
+	int    *ptr;
+} types_t;
+
+// Arrays.
+typedef int myIntArray[10];
+
+// Bitfields.
+typedef struct {
+	unsigned char start;
+	unsigned char a : 5;
+	unsigned char b : 1;
+	unsigned char c : 2;
+	unsigned char :0; // new field
+	unsigned char d : 6;
+	unsigned char e : 3;
+	// Note that C++ allows bitfields bigger than the underlying type.
+} bitfield_t;
+
+// Function signatures.
+void variadic0();
+void variadic2(int x, int y, ...);
+*/
+import "C"
+
+var (
+	// Simple typedefs.
+	_ C.myint
+
+	// Structs.
+	_ C.point2d_t
+	_ C.point3d_t
+	_ C.struct_point3d
+
+	// Structs with reserved field names.
+	_ C.struct_type1
+	_ C.struct_type2
+
+	// Unions.
+	_ C.union1_t
+	_ C.union3_t
+	_ C.union2d_t
+	_ C.unionarray_t
+
+	// Nested structs and unions.
+	_ C.struct_nested_t
+	_ C.union_nested_t
+
+	// Enums (anonymous and named).
+	_ C.option_t
+	_ C.enum_option
+	_ C.option2_t
+
+	// Various types.
+	_ C.types_t
+
+	// Arrays.
+	_ C.myIntArray
+)
+
+// Test bitfield accesses.
+func accessBitfields() {
+	var x C.bitfield_t
+	x.start = 3
+	x.set_bitfield_a(4)
+	x.set_bitfield_b(1)
+	x.set_bitfield_c(2)
+	x.d = 10
+	x.e = 5
+	var _ C.uchar = x.bitfield_a()
+}
+
+// Test union accesses.
+func accessUnion() {
+	var union1 C.union1_t
+	union1.i = 5
+
+	var union2d C.union2d_t
+	var _ *C.int = union2d.unionfield_i()
+	var _ *[2]float64 = union2d.unionfield_d()
+}
+
+// Test function signatures.
+func accessFunctions() {
+	C.variadic0()
+	C.variadic2(3, 5)
+}

cgo/testdata/types.out.go

@@ -0,0 +1,150 @@
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+func C.variadic0() //go:variadic
+func C.variadic2(x C.int, y C.int) //go:variadic
+var C.variadic0$funcaddr unsafe.Pointer
+var C.variadic2$funcaddr unsafe.Pointer
+
+const C.option2A = 20
+const C.optionA = 0
+const C.optionB = 1
+const C.optionC = -5
+const C.optionD = -4
+const C.optionE = 10
+const C.optionF = 11
+const C.optionG = 12
+const C.unused1 = 5
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16
+type C.bitfield_t = C.struct_4
+type C.myIntArray = [10]C.int
+type C.myint = C.int
+type C.option2_t = C.uint
+type C.option_t = C.enum_option
+type C.point2d_t = struct {
+	x C.int
+	y C.int
+}
+type C.point3d_t = C.struct_point3d
+type C.struct_nested_t = struct {
+	begin C.point2d_t
+	end   C.point2d_t
+	tag   C.int
+
+	coord C.union_2
+}
+type C.types_t = struct {
+	f   float32
+	d   float64
+	ptr *C.int
+}
+type C.union1_t = struct{ i C.int }
+type C.union2d_t = C.union_union2d
+type C.union3_t = C.union_1
+type C.union_nested_t = C.union_3
+type C.unionarray_t = struct{ arr [10]C.uchar }
+
+func (s *C.struct_4) bitfield_a() C.uchar {
+	return s.__bitfield_1 & 0x1f
+}
+func (s *C.struct_4) set_bitfield_a(value C.uchar) {
+	s.__bitfield_1 = s.__bitfield_1&^0x1f | value&0x1f<<0
+}
+func (s *C.struct_4) bitfield_b() C.uchar {
+	return s.__bitfield_1 >> 5 & 0x1
+}
+func (s *C.struct_4) set_bitfield_b(value C.uchar) {
+	s.__bitfield_1 = s.__bitfield_1&^0x20 | value&0x1<<5
+}
+func (s *C.struct_4) bitfield_c() C.uchar {
+	return s.__bitfield_1 >> 6
+}
+func (s *C.struct_4) set_bitfield_c(value C.uchar,
+
+) { s.__bitfield_1 = s.__bitfield_1&0x3f | value<<6 }
+
+type C.struct_4 struct {
+	start        C.uchar
+	__bitfield_1 C.uchar
+
+	d C.uchar
+	e C.uchar
+}
+type C.struct_point3d struct {
+	x C.int
+	y C.int
+	z C.int
+}
+type C.struct_type1 struct {
+	_type   C.int
+	__type  C.int
+	___type C.int
+}
+type C.struct_type2 struct{ _type C.int }
+
+func (union *C.union_1) unionfield_i() *C.int {
+	return (*C.int)(unsafe.Pointer(&union.$union))
+}
+func (union *C.union_1) unionfield_d() *float64 {
+	return (*float64)(unsafe.Pointer(&union.$union))
+}
+func (union *C.union_1) unionfield_s() *C.short {
+	return (*C.short)(unsafe.Pointer(&union.$union))
+}
+
+type C.union_1 struct{ $union uint64 }
+
+func (union *C.union_2) unionfield_area() *C.point2d_t {
+	return (*C.point2d_t)(unsafe.Pointer(&union.$union))
+}
+func (union *C.union_2) unionfield_solid() *C.point3d_t {
+	return (*C.point3d_t)(unsafe.Pointer(&union.$union))
+}
+
+type C.union_2 struct{ $union [3]uint32 }
+
+func (union *C.union_3) unionfield_point() *C.point3d_t {
+	return (*C.point3d_t)(unsafe.Pointer(&union.$union))
+}
+func (union *C.union_3) unionfield_array() *C.unionarray_t {
+	return (*C.unionarray_t)(unsafe.Pointer(&union.$union))
+}
+func (union *C.union_3) unionfield_thing() *C.union3_t {
+	return (*C.union3_t)(unsafe.Pointer(&union.$union))
+}
+
+type C.union_3 struct{ $union [2]uint64 }
+
+func (union *C.union_union2d) unionfield_i() *C.int {
+	return (*C.int)(unsafe.Pointer(&union.$union))
+}
+func (union *C.union_union2d) unionfield_d() *[2]float64 {
+	return (*[2]float64)(unsafe.Pointer(&union.$union))
+}
+
+type C.union_union2d struct{ $union [2]uint64 }
+type C.enum_option C.int
+type C.enum_unused C.uint

compileopts/config.go

@@ -0,0 +1,327 @@
+// Package compileopts contains the configuration for a single to-be-built
+// binary.
+package compileopts
+
+import (
+	"errors"
+	"fmt"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// Config keeps all configuration affecting the build in a single struct.
+type Config struct {
+	Options        *Options
+	Target         *TargetSpec
+	GoMinorVersion int
+	ClangHeaders   string // Clang built-in header include path
+	TestConfig     TestConfig
+}
+
+// Triple returns the LLVM target triple, like armv6m-none-eabi.
+func (c *Config) Triple() string {
+	return c.Target.Triple
+}
+
+// CPU returns the LLVM CPU name, like atmega328p or arm7tdmi. It may return an
+// empty string if the CPU name is not known.
+func (c *Config) CPU() string {
+	return c.Target.CPU
+}
+
+// Features returns a list of features this CPU supports. For example, for a
+// RISC-V processor, that could be ["+a", "+c", "+m"]. For many targets, an
+// empty list will be returned.
+func (c *Config) Features() []string {
+	return c.Target.Features
+}
+
+// GOOS returns the GOOS of the target. This might not always be the actual OS:
+// for example, bare-metal targets will usually pretend to be linux to get the
+// standard library to compile.
+func (c *Config) GOOS() string {
+	return c.Target.GOOS
+}
+
+// GOARCH returns the GOARCH of the target. This might not always be the actual
+// archtecture: for example, the AVR target is not supported by the Go standard
+// library so such targets will usually pretend to be linux/arm.
+func (c *Config) GOARCH() string {
+	return c.Target.GOARCH
+}
+
+// BuildTags returns the complete list of build tags used during this build.
+func (c *Config) BuildTags() []string {
+	tags := append(c.Target.BuildTags, []string{"tinygo", "gc." + c.GC(), "scheduler." + c.Scheduler()}...)
+	for i := 1; i <= c.GoMinorVersion; i++ {
+		tags = append(tags, fmt.Sprintf("go1.%d", i))
+	}
+	if extraTags := strings.Fields(c.Options.Tags); len(extraTags) != 0 {
+		tags = append(tags, extraTags...)
+	}
+	return tags
+}
+
+// CgoEnabled returns true if (and only if) CGo is enabled. It is true by
+// default and false if CGO_ENABLED is set to "0".
+func (c *Config) CgoEnabled() bool {
+	return goenv.Get("CGO_ENABLED") == "1"
+}
+
+// GC returns the garbage collection strategy in use on this platform. Valid
+// values are "none", "leaking", "extalloc", and "conservative".
+func (c *Config) GC() string {
+	if c.Options.GC != "" {
+		return c.Options.GC
+	}
+	if c.Target.GC != "" {
+		return c.Target.GC
+	}
+	for _, tag := range c.Target.BuildTags {
+		if tag == "baremetal" || tag == "wasm" {
+			return "conservative"
+		}
+	}
+	return "extalloc"
+}
+
+// NeedsStackObjects returns true if the compiler should insert stack objects
+// that can be traced by the garbage collector.
+func (c *Config) NeedsStackObjects() bool {
+	switch c.GC() {
+	case "conservative", "extalloc":
+		for _, tag := range c.BuildTags() {
+			if tag == "wasm" {
+				return true
+			}
+		}
+
+		return false
+	default:
+		return false
+	}
+}
+
+// Scheduler returns the scheduler implementation. Valid values are "none",
+//"coroutines" and "tasks".
+func (c *Config) Scheduler() string {
+	if c.Options.Scheduler != "" {
+		return c.Options.Scheduler
+	}
+	if c.Target.Scheduler != "" {
+		return c.Target.Scheduler
+	}
+	// Fall back to coroutines, which are supported everywhere.
+	return "coroutines"
+}
+
+// FuncImplementation picks an appropriate func value implementation for the
+// target.
+func (c *Config) FuncImplementation() string {
+	switch c.Scheduler() {
+	case "tasks":
+		// A func value is implemented as a pair of pointers:
+		//     {context, function pointer}
+		// where the context may be a pointer to a heap-allocated struct
+		// containing the free variables, or it may be undef if the function
+		// being pointed to doesn't need a context. The function pointer is a
+		// regular function pointer.
+		return "doubleword"
+	case "none", "coroutines":
+		// As "doubleword", but with the function pointer replaced by a unique
+		// ID per function signature. Function values are called by using a
+		// switch statement and choosing which function to call.
+		// Pick the switch implementation with the coroutines scheduler, as it
+		// allows the use of blocking inside a function that is used as a func
+		// value.
+		return "switch"
+	default:
+		panic("unknown scheduler type")
+	}
+}
+
+// PanicStrategy returns the panic strategy selected for this target. Valid
+// values are "print" (print the panic value, then exit) or "trap" (issue a trap
+// instruction).
+func (c *Config) PanicStrategy() string {
+	return c.Options.PanicStrategy
+}
+
+// AutomaticStackSize returns whether goroutine stack sizes should be determined
+// automatically at compile time, if possible. If it is false, no attempt is
+// made.
+func (c *Config) AutomaticStackSize() bool {
+	if c.Target.AutoStackSize != nil && c.Scheduler() == "tasks" {
+		return *c.Target.AutoStackSize
+	}
+	return false
+}
+
+// CFlags returns the flags to pass to the C compiler. This is necessary for CGo
+// preprocessing.
+func (c *Config) CFlags() []string {
+	cflags := append([]string{}, c.Options.CFlags...)
+	for _, flag := range c.Target.CFlags {
+		cflags = append(cflags, strings.ReplaceAll(flag, "{root}", goenv.Get("TINYGOROOT")))
+	}
+	if c.Target.Libc == "picolibc" {
+		root := goenv.Get("TINYGOROOT")
+		cflags = append(cflags, "-nostdlibinc", "-Xclang", "-internal-isystem", "-Xclang", filepath.Join(root, "lib", "picolibc", "newlib", "libc", "include"))
+		cflags = append(cflags, "-I"+filepath.Join(root, "lib/picolibc-include"))
+	}
+	if c.Debug() {
+		cflags = append(cflags, "-g")
+	}
+	return cflags
+}
+
+// LDFlags returns the flags to pass to the linker. A few more flags are needed
+// (like the one for the compiler runtime), but this represents the majority of
+// the flags.
+func (c *Config) LDFlags() []string {
+	root := goenv.Get("TINYGOROOT")
+	// Merge and adjust LDFlags.
+	ldflags := append([]string{}, c.Options.LDFlags...)
+	for _, flag := range c.Target.LDFlags {
+		ldflags = append(ldflags, strings.ReplaceAll(flag, "{root}", root))
+	}
+	ldflags = append(ldflags, "-L", root)
+	if c.Target.LinkerScript != "" {
+		ldflags = append(ldflags, "-T", c.Target.LinkerScript)
+	}
+	return ldflags
+}
+
+// ExtraFiles returns the list of extra files to be built and linked with the
+// executable. This can include extra C and assembly files.
+func (c *Config) ExtraFiles() []string {
+	return c.Target.ExtraFiles
+}
+
+// DumpSSA returns whether to dump Go SSA while compiling (-dumpssa flag). Only
+// enable this for debugging.
+func (c *Config) DumpSSA() bool {
+	return c.Options.DumpSSA
+}
+
+// VerifyIR returns whether to run extra checks on the IR. This is normally
+// disabled but enabled during testing.
+func (c *Config) VerifyIR() bool {
+	return c.Options.VerifyIR
+}
+
+// Debug returns whether to add debug symbols to the IR, for debugging with GDB
+// and similar.
+func (c *Config) Debug() bool {
+	return c.Options.Debug
+}
+
+// BinaryFormat returns an appropriate binary format, based on the file
+// extension and the configured binary format in the target JSON file.
+func (c *Config) BinaryFormat(ext string) string {
+	switch ext {
+	case ".bin", ".gba", ".nro":
+		// The simplest format possible: dump everything in a raw binary file.
+		if c.Target.BinaryFormat != "" {
+			return c.Target.BinaryFormat
+		}
+		return "bin"
+	case ".hex":
+		// Similar to bin, but includes the start address and is thus usually a
+		// better format.
+		return "hex"
+	case ".uf2":
+		// Special purpose firmware format, mainly used on Adafruit boards.
+		// More information:
+		// https://github.com/Microsoft/uf2
+		return "uf2"
+	default:
+		// Use the ELF format for unrecognized file formats.
+		return "elf"
+	}
+}
+
+// Programmer returns the flash method and OpenOCD interface name given a
+// particular configuration. It may either be all configured in the target JSON
+// file or be modified using the -programmmer command-line option.
+func (c *Config) Programmer() (method, openocdInterface string) {
+	switch c.Options.Programmer {
+	case "":
+		// No configuration supplied.
+		return c.Target.FlashMethod, c.Target.OpenOCDInterface
+	case "openocd", "msd", "command":
+		// The -programmer flag only specifies the flash method.
+		return c.Options.Programmer, c.Target.OpenOCDInterface
+	default:
+		// The -programmer flag specifies something else, assume it specifies
+		// the OpenOCD interface name.
+		return "openocd", c.Options.Programmer
+	}
+}
+
+// OpenOCDConfiguration returns a list of command line arguments to OpenOCD.
+// This list of command-line arguments is based on the various OpenOCD-related
+// flags in the target specification.
+func (c *Config) OpenOCDConfiguration() (args []string, err error) {
+	_, openocdInterface := c.Programmer()
+	if openocdInterface == "" {
+		return nil, errors.New("OpenOCD programmer not set")
+	}
+	if !regexp.MustCompile("^[\\p{L}0-9_-]+$").MatchString(openocdInterface) {
+		return nil, fmt.Errorf("OpenOCD programmer has an invalid name: %#v", openocdInterface)
+	}
+	if c.Target.OpenOCDTarget == "" {
+		return nil, errors.New("OpenOCD chip not set")
+	}
+	if !regexp.MustCompile("^[\\p{L}0-9_-]+$").MatchString(c.Target.OpenOCDTarget) {
+		return nil, fmt.Errorf("OpenOCD target has an invalid name: %#v", c.Target.OpenOCDTarget)
+	}
+	if c.Target.OpenOCDTransport != "" && c.Target.OpenOCDTransport != "swd" {
+		return nil, fmt.Errorf("unknown OpenOCD transport: %#v", c.Target.OpenOCDTransport)
+	}
+	args = []string{"-f", "interface/" + openocdInterface + ".cfg"}
+	for _, cmd := range c.Target.OpenOCDCommands {
+		args = append(args, "-c", cmd)
+	}
+	if c.Target.OpenOCDTransport != "" {
+		args = append(args, "-c", "transport select "+c.Target.OpenOCDTransport)
+	}
+	args = append(args, "-f", "target/"+c.Target.OpenOCDTarget+".cfg")
+	return args, nil
+}
+
+// CodeModel returns the code model used on this platform.
+func (c *Config) CodeModel() string {
+	if c.Target.CodeModel != "" {
+		return c.Target.CodeModel
+	}
+
+	return "default"
+}
+
+// RelocationModel returns the relocation model in use on this platform. Valid
+// values are "static", "pic", "dynamicnopic".
+func (c *Config) RelocationModel() string {
+	if c.Target.RelocationModel != "" {
+		return c.Target.RelocationModel
+	}
+
+	return "static"
+}
+
+// WasmAbi returns the WASM ABI which is specified in the target JSON file, and
+// the value is overridden by `-wasm-abi` flag if it is provided
+func (c *Config) WasmAbi() string {
+	if c.Options.WasmAbi != "" {
+		return c.Options.WasmAbi
+	}
+	return c.Target.WasmAbi
+}
+
+type TestConfig struct {
+	CompileTestBinary bool
+	// TODO: Filter the test functions to run, include verbose flag, etc
+}

compileopts/options.go

@@ -0,0 +1,86 @@
+package compileopts
+
+import (
+	"fmt"
+	"strings"
+)
+
+var (
+	validGCOptions            = []string{"none", "leaking", "extalloc", "conservative"}
+	validSchedulerOptions     = []string{"none", "tasks", "coroutines"}
+	validPrintSizeOptions     = []string{"none", "short", "full"}
+	validPanicStrategyOptions = []string{"print", "trap"}
+)
+
+// Options contains extra options to give to the compiler. These options are
+// usually passed from the command line.
+type Options struct {
+	Target        string
+	Opt           string
+	GC            string
+	PanicStrategy string
+	Scheduler     string
+	PrintIR       bool
+	DumpSSA       bool
+	VerifyIR      bool
+	PrintCommands bool
+	Debug         bool
+	PrintSizes    string
+	PrintStacks   bool
+	CFlags        []string
+	LDFlags       []string
+	Tags          string
+	WasmAbi       string
+	TestConfig    TestConfig
+	Programmer    string
+}
+
+// Verify performs a validation on the given options, raising an error if options are not valid.
+func (o *Options) Verify() error {
+	if o.GC != "" {
+		valid := isInArray(validGCOptions, o.GC)
+		if !valid {
+			return fmt.Errorf(`invalid gc option '%s': valid values are %s`,
+				o.GC,
+				strings.Join(validGCOptions, ", "))
+		}
+	}
+
+	if o.Scheduler != "" {
+		valid := isInArray(validSchedulerOptions, o.Scheduler)
+		if !valid {
+			return fmt.Errorf(`invalid scheduler option '%s': valid values are %s`,
+				o.Scheduler,
+				strings.Join(validSchedulerOptions, ", "))
+		}
+	}
+
+	if o.PrintSizes != "" {
+		valid := isInArray(validPrintSizeOptions, o.PrintSizes)
+		if !valid {
+			return fmt.Errorf(`invalid size option '%s': valid values are %s`,
+				o.PrintSizes,
+				strings.Join(validPrintSizeOptions, ", "))
+		}
+	}
+
+	if o.PanicStrategy != "" {
+		valid := isInArray(validPanicStrategyOptions, o.PanicStrategy)
+		if !valid {
+			return fmt.Errorf(`invalid panic option '%s': valid values are %s`,
+				o.PanicStrategy,
+				strings.Join(validPanicStrategyOptions, ", "))
+		}
+	}
+
+	return nil
+}
+
+func isInArray(arr []string, item string) bool {
+	for _, i := range arr {
+		if i == item {
+			return true
+		}
+	}
+	return false
+}

compileopts/options_test.go

@@ -0,0 +1,138 @@
+package compileopts_test
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+)
+
+func TestVerifyOptions(t *testing.T) {
+
+	expectedGCError := errors.New(`invalid gc option 'incorrect': valid values are none, leaking, extalloc, conservative`)
+	expectedSchedulerError := errors.New(`invalid scheduler option 'incorrect': valid values are none, tasks, coroutines`)
+	expectedPrintSizeError := errors.New(`invalid size option 'incorrect': valid values are none, short, full`)
+	expectedPanicStrategyError := errors.New(`invalid panic option 'incorrect': valid values are print, trap`)
+
+	testCases := []struct {
+		name          string
+		opts          compileopts.Options
+		expectedError error
+	}{
+		{
+			name: "OptionsEmpty",
+			opts: compileopts.Options{},
+		},
+		{
+			name: "InvalidGCOption",
+			opts: compileopts.Options{
+				GC: "incorrect",
+			},
+			expectedError: expectedGCError,
+		},
+		{
+			name: "GCOptionNone",
+			opts: compileopts.Options{
+				GC: "none",
+			},
+		},
+		{
+			name: "GCOptionLeaking",
+			opts: compileopts.Options{
+				GC: "leaking",
+			},
+		},
+		{
+			name: "GCOptionExtalloc",
+			opts: compileopts.Options{
+				GC: "extalloc",
+			},
+		},
+		{
+			name: "GCOptionConservative",
+			opts: compileopts.Options{
+				GC: "conservative",
+			},
+		},
+		{
+			name: "InvalidSchedulerOption",
+			opts: compileopts.Options{
+				Scheduler: "incorrect",
+			},
+			expectedError: expectedSchedulerError,
+		},
+		{
+			name: "SchedulerOptionNone",
+			opts: compileopts.Options{
+				Scheduler: "none",
+			},
+		},
+		{
+			name: "SchedulerOptionTasks",
+			opts: compileopts.Options{
+				Scheduler: "tasks",
+			},
+		},
+		{
+			name: "SchedulerOptionCoroutines",
+			opts: compileopts.Options{
+				Scheduler: "coroutines",
+			},
+		},
+		{
+			name: "InvalidPrintSizeOption",
+			opts: compileopts.Options{
+				PrintSizes: "incorrect",
+			},
+			expectedError: expectedPrintSizeError,
+		},
+		{
+			name: "PrintSizeOptionNone",
+			opts: compileopts.Options{
+				PrintSizes: "none",
+			},
+		},
+		{
+			name: "PrintSizeOptionShort",
+			opts: compileopts.Options{
+				PrintSizes: "short",
+			},
+		},
+		{
+			name: "PrintSizeOptionFull",
+			opts: compileopts.Options{
+				PrintSizes: "full",
+			},
+		},
+		{
+			name: "InvalidPanicOption",
+			opts: compileopts.Options{
+				PanicStrategy: "incorrect",
+			},
+			expectedError: expectedPanicStrategyError,
+		},
+		{
+			name: "PanicOptionPrint",
+			opts: compileopts.Options{
+				PanicStrategy: "print",
+			},
+		},
+		{
+			name: "PanicOptionTrap",
+			opts: compileopts.Options{
+				PanicStrategy: "trap",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := tc.opts.Verify()
+			if tc.expectedError != err {
+				if tc.expectedError.Error() != err.Error() {
+					t.Errorf("expected %v, got %v", tc.expectedError, err)
+				}
+			}
+		})
+	}
+}

compileopts/target.go

@@ -0,0 +1,288 @@
+package compileopts
+
+// This file loads a target specification from a JSON file.
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// Target specification for a given target. Used for bare metal targets.
+//
+// The target specification is mostly inspired by Rust:
+// https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/spec/struct.TargetOptions.html
+// https://github.com/shepmaster/rust-arduino-blink-led-no-core-with-cargo/blob/master/blink/arduino.json
+type TargetSpec struct {
+	Inherits         []string `json:"inherits"`
+	Triple           string   `json:"llvm-target"`
+	CPU              string   `json:"cpu"`
+	Features         []string `json:"features"`
+	GOOS             string   `json:"goos"`
+	GOARCH           string   `json:"goarch"`
+	BuildTags        []string `json:"build-tags"`
+	GC               string   `json:"gc"`
+	Scheduler        string   `json:"scheduler"`
+	Compiler         string   `json:"compiler"`
+	Linker           string   `json:"linker"`
+	RTLib            string   `json:"rtlib"` // compiler runtime library (libgcc, compiler-rt)
+	Libc             string   `json:"libc"`
+	AutoStackSize    *bool    `json:"automatic-stack-size"` // Determine stack size automatically at compile time.
+	DefaultStackSize uint64   `json:"default-stack-size"`   // Default stack size if the size couldn't be determined at compile time.
+	CFlags           []string `json:"cflags"`
+	LDFlags          []string `json:"ldflags"`
+	LinkerScript     string   `json:"linkerscript"`
+	ExtraFiles       []string `json:"extra-files"`
+	Emulator         []string `json:"emulator" override:"copy"` // inherited Emulator must not be append
+	FlashCommand     string   `json:"flash-command"`
+	GDB              []string `json:"gdb"`
+	PortReset        string   `json:"flash-1200-bps-reset"`
+	FlashMethod      string   `json:"flash-method"`
+	FlashVolume      string   `json:"msd-volume-name"`
+	FlashFilename    string   `json:"msd-firmware-name"`
+	UF2FamilyID      string   `json:"uf2-family-id"`
+	BinaryFormat     string   `json:"binary-format"`
+	OpenOCDInterface string   `json:"openocd-interface"`
+	OpenOCDTarget    string   `json:"openocd-target"`
+	OpenOCDTransport string   `json:"openocd-transport"`
+	OpenOCDCommands  []string `json:"openocd-commands"`
+	JLinkDevice      string   `json:"jlink-device"`
+	CodeModel        string   `json:"code-model"`
+	RelocationModel  string   `json:"relocation-model"`
+	WasmAbi          string   `json:"wasm-abi"`
+}
+
+// overrideProperties overrides all properties that are set in child into itself using reflection.
+func (spec *TargetSpec) overrideProperties(child *TargetSpec) {
+	specType := reflect.TypeOf(spec).Elem()
+	specValue := reflect.ValueOf(spec).Elem()
+	childValue := reflect.ValueOf(child).Elem()
+
+	for i := 0; i < specType.NumField(); i++ {
+		field := specType.Field(i)
+		src := childValue.Field(i)
+		dst := specValue.Field(i)
+
+		switch kind := field.Type.Kind(); kind {
+		case reflect.String: // for strings, just copy the field of child to spec if not empty
+			if src.Len() > 0 {
+				dst.Set(src)
+			}
+		case reflect.Uint, reflect.Uint32, reflect.Uint64: // for Uint, copy if not zero
+			if src.Uint() != 0 {
+				dst.Set(src)
+			}
+		case reflect.Ptr: // for pointers, copy if not nil
+			if !src.IsNil() {
+				dst.Set(src)
+			}
+		case reflect.Slice: // for slices...
+			if src.Len() > 0 { // ... if not empty ...
+				switch tag := field.Tag.Get("override"); tag {
+				case "copy":
+					// copy the field of child to spec
+					dst.Set(src)
+				case "append", "":
+					// or append the field of child to spec
+					dst.Set(reflect.AppendSlice(src, dst))
+				default:
+					panic("override mode must be 'copy' or 'append' (default). I don't know how to '" + tag + "'.")
+				}
+			}
+		default:
+			panic("unknown field type : " + kind.String())
+		}
+	}
+}
+
+// load reads a target specification from the JSON in the given io.Reader. It
+// may load more targets specified using the "inherits" property.
+func (spec *TargetSpec) load(r io.Reader) error {
+	err := json.NewDecoder(r).Decode(spec)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// loadFromGivenStr loads the TargetSpec from the given string that could be:
+// - targets/ directory inside the compiler sources
+// - a relative or absolute path to custom (project specific) target specification .json file;
+//   the Inherits[] could contain the files from target folder (ex. stm32f4disco)
+//   as well as path to custom files (ex. myAwesomeProject.json)
+func (spec *TargetSpec) loadFromGivenStr(str string) error {
+	path := ""
+	if strings.HasSuffix(str, ".json") {
+		path, _ = filepath.Abs(str)
+	} else {
+		path = filepath.Join(goenv.Get("TINYGOROOT"), "targets", strings.ToLower(str)+".json")
+	}
+	fp, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+	return spec.load(fp)
+}
+
+// resolveInherits loads inherited targets, recursively.
+func (spec *TargetSpec) resolveInherits() error {
+	// First create a new spec with all the inherited properties.
+	newSpec := &TargetSpec{}
+	for _, name := range spec.Inherits {
+		subtarget := &TargetSpec{}
+		err := subtarget.loadFromGivenStr(name)
+		if err != nil {
+			return err
+		}
+		err = subtarget.resolveInherits()
+		if err != nil {
+			return err
+		}
+		newSpec.overrideProperties(subtarget)
+	}
+
+	// When all properties are loaded, make sure they are properly inherited.
+	newSpec.overrideProperties(spec)
+	*spec = *newSpec
+
+	return nil
+}
+
+// Load a target specification.
+func LoadTarget(target string) (*TargetSpec, error) {
+	if target == "" {
+		// Configure based on GOOS/GOARCH environment variables (falling back to
+		// runtime.GOOS/runtime.GOARCH), and generate a LLVM target based on it.
+		goos := goenv.Get("GOOS")
+		goarch := goenv.Get("GOARCH")
+		llvmos := goos
+		llvmarch := map[string]string{
+			"386":   "i386",
+			"amd64": "x86_64",
+			"arm64": "aarch64",
+		}[goarch]
+		if llvmarch == "" {
+			llvmarch = goarch
+		}
+		target = llvmarch + "--" + llvmos
+		if goarch == "arm" {
+			target += "-gnueabihf"
+		}
+		return defaultTarget(goos, goarch, target)
+	}
+
+	// See whether there is a target specification for this target (e.g.
+	// Arduino).
+	spec := &TargetSpec{}
+	err := spec.loadFromGivenStr(target)
+	if err == nil {
+		// Successfully loaded this target from a built-in .json file. Make sure
+		// it includes all parents as specified in the "inherits" key.
+		err = spec.resolveInherits()
+		if err != nil {
+			return nil, err
+		}
+		return spec, nil
+	} else if !os.IsNotExist(err) {
+		// Expected a 'file not found' error, got something else. Report it as
+		// an error.
+		return nil, err
+	} else {
+		// Load target from given triple, ignore GOOS/GOARCH environment
+		// variables.
+		tripleSplit := strings.Split(target, "-")
+		if len(tripleSplit) < 3 {
+			return nil, errors.New("expected a full LLVM target or a custom target in -target flag")
+		}
+		if tripleSplit[0] == "arm" {
+			// LLVM and Clang have a different idea of what "arm" means, so
+			// upgrade to a slightly more modern ARM. In fact, when you pass
+			// --target=arm--linux-gnueabihf to Clang, it will convert that
+			// internally to armv7-unknown-linux-gnueabihf. Changing the
+			// architecture to armv7 will keep things consistent.
+			tripleSplit[0] = "armv7"
+		}
+		goos := tripleSplit[2]
+		if strings.HasPrefix(goos, "darwin") {
+			goos = "darwin"
+		}
+		goarch := map[string]string{ // map from LLVM arch to Go arch
+			"i386":    "386",
+			"i686":    "386",
+			"x86_64":  "amd64",
+			"aarch64": "arm64",
+			"armv7":   "arm",
+		}[tripleSplit[0]]
+		if goarch == "" {
+			goarch = tripleSplit[0]
+		}
+		return defaultTarget(goos, goarch, strings.Join(tripleSplit, "-"))
+	}
+}
+
+func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
+	// No target spec available. Use the default one, useful on most systems
+	// with a regular OS.
+	spec := TargetSpec{
+		Triple:    triple,
+		GOOS:      goos,
+		GOARCH:    goarch,
+		BuildTags: []string{goos, goarch},
+		Compiler:  "clang",
+		Linker:    "cc",
+		CFlags:    []string{"--target=" + triple},
+		GDB:       []string{"gdb"},
+		PortReset: "false",
+	}
+	if goos == "darwin" {
+		spec.LDFlags = append(spec.LDFlags, "-Wl,-dead_strip")
+	} else {
+		spec.LDFlags = append(spec.LDFlags, "-no-pie", "-Wl,--gc-sections") // WARNING: clang < 5.0 requires -nopie
+	}
+	if goarch != "wasm" {
+		spec.ExtraFiles = append(spec.ExtraFiles, "src/runtime/gc_"+goarch+".S")
+	}
+	if goarch != runtime.GOARCH {
+		// Some educated guesses as to how to invoke helper programs.
+		spec.GDB = []string{"gdb-multiarch"}
+		if goarch == "arm" && goos == "linux" {
+			spec.CFlags = append(spec.CFlags, "--sysroot=/usr/arm-linux-gnueabihf")
+			spec.Linker = "arm-linux-gnueabihf-gcc"
+			spec.Emulator = []string{"qemu-arm", "-L", "/usr/arm-linux-gnueabihf"}
+		}
+		if goarch == "arm64" && goos == "linux" {
+			spec.CFlags = append(spec.CFlags, "--sysroot=/usr/aarch64-linux-gnu")
+			spec.Linker = "aarch64-linux-gnu-gcc"
+			spec.Emulator = []string{"qemu-aarch64", "-L", "/usr/aarch64-linux-gnu"}
+		}
+		if goarch == "386" && runtime.GOARCH == "amd64" {
+			spec.CFlags = append(spec.CFlags, "-m32")
+			spec.LDFlags = append(spec.LDFlags, "-m32")
+		}
+	}
+	return &spec, nil
+}
+
+// LookupGDB looks up a gdb executable.
+func (spec *TargetSpec) LookupGDB() (string, error) {
+	if len(spec.GDB) == 0 {
+		return "", errors.New("gdb not configured in the target specification")
+	}
+	for _, d := range spec.GDB {
+		_, err := exec.LookPath(d)
+		if err == nil {
+			return d, nil
+		}
+	}
+	return "", errors.New("no gdb found configured in the target specification (" + strings.Join(spec.GDB, ", ") + ")")
+}

compileopts/target_test.go

@@ -0,0 +1,86 @@
+package compileopts
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestLoadTarget(t *testing.T) {
+	_, err := LoadTarget("arduino")
+	if err != nil {
+		t.Error("LoadTarget test failed:", err)
+	}
+
+	_, err = LoadTarget("notexist")
+	if err == nil {
+		t.Error("LoadTarget should have failed with non existing target")
+	}
+
+	if err.Error() != "expected a full LLVM target or a custom target in -target flag" {
+		t.Error("LoadTarget failed for wrong reason:", err)
+	}
+}
+
+func TestOverrideProperties(t *testing.T) {
+	baseAutoStackSize := true
+	base := &TargetSpec{
+		GOOS:             "baseGoos",
+		CPU:              "baseCpu",
+		Features:         []string{"bf1", "bf2"},
+		BuildTags:        []string{"bt1", "bt2"},
+		Emulator:         []string{"be1", "be2"},
+		DefaultStackSize: 42,
+		AutoStackSize:    &baseAutoStackSize,
+	}
+	childAutoStackSize := false
+	child := &TargetSpec{
+		GOOS:             "",
+		CPU:              "chlidCpu",
+		Features:         []string{"cf1", "cf2"},
+		Emulator:         []string{"ce1", "ce2"},
+		AutoStackSize:    &childAutoStackSize,
+		DefaultStackSize: 64,
+	}
+
+	base.overrideProperties(child)
+
+	if base.GOOS != "baseGoos" {
+		t.Errorf("Overriding failed : got %v", base.GOOS)
+	}
+	if base.CPU != "chlidCpu" {
+		t.Errorf("Overriding failed : got %v", base.CPU)
+	}
+	if !reflect.DeepEqual(base.Features, []string{"cf1", "cf2", "bf1", "bf2"}) {
+		t.Errorf("Overriding failed : got %v", base.Features)
+	}
+	if !reflect.DeepEqual(base.BuildTags, []string{"bt1", "bt2"}) {
+		t.Errorf("Overriding failed : got %v", base.BuildTags)
+	}
+	if !reflect.DeepEqual(base.Emulator, []string{"ce1", "ce2"}) {
+		t.Errorf("Overriding failed : got %v", base.Emulator)
+	}
+	if *base.AutoStackSize != false {
+		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
+	}
+	if base.DefaultStackSize != 64 {
+		t.Errorf("Overriding failed : got %v", base.DefaultStackSize)
+	}
+
+	baseAutoStackSize = true
+	base = &TargetSpec{
+		AutoStackSize:    &baseAutoStackSize,
+		DefaultStackSize: 42,
+	}
+	child = &TargetSpec{
+		AutoStackSize:    nil,
+		DefaultStackSize: 0,
+	}
+	base.overrideProperties(child)
+	if *base.AutoStackSize != true {
+		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
+	}
+	if base.DefaultStackSize != 42 {
+		t.Errorf("Overriding failed : got %v", base.DefaultStackSize)
+	}
+
+}

compiler/asserts.go

@@ -0,0 +1,232 @@
+package compiler
+
+// This file implements functions that do certain safety checks that are
+// required by the Go programming language.
+
+import (
+	"fmt"
+	"go/token"
+	"go/types"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createLookupBoundsCheck emits a bounds check before doing a lookup into a
+// slice. This is required by the Go language spec: an index out of bounds must
+// cause a panic.
+func (b *builder) createLookupBoundsCheck(arrayLen, index llvm.Value, indexType types.Type) {
+	if b.info.nobounds {
+		// The //go:nobounds pragma was added to the function to avoid bounds
+		// checking.
+		return
+	}
+
+	if index.Type().IntTypeWidth() < arrayLen.Type().IntTypeWidth() {
+		// Sometimes, the index can be e.g. an uint8 or int8, and we have to
+		// correctly extend that type.
+		if indexType.Underlying().(*types.Basic).Info()&types.IsUnsigned == 0 {
+			index = b.CreateZExt(index, arrayLen.Type(), "")
+		} else {
+			index = b.CreateSExt(index, arrayLen.Type(), "")
+		}
+	} else if index.Type().IntTypeWidth() > arrayLen.Type().IntTypeWidth() {
+		// The index is bigger than the array length type, so extend it.
+		arrayLen = b.CreateZExt(arrayLen, index.Type(), "")
+	}
+
+	// Now do the bounds check: index >= arrayLen
+	outOfBounds := b.CreateICmp(llvm.IntUGE, index, arrayLen, "")
+	b.createRuntimeAssert(outOfBounds, "lookup", "lookupPanic")
+}
+
+// createSliceBoundsCheck emits a bounds check before a slicing operation to make
+// sure it is within bounds.
+//
+// This function is both used for slicing a slice (low and high have their
+// normal meaning) and for creating a new slice, where 'capacity' means the
+// biggest possible slice capacity, 'low' means len and 'high' means cap. The
+// logic is the same in both cases.
+func (b *builder) createSliceBoundsCheck(capacity, low, high, max llvm.Value, lowType, highType, maxType *types.Basic) {
+	if b.info.nobounds {
+		// The //go:nobounds pragma was added to the function to avoid bounds
+		// checking.
+		return
+	}
+
+	// Extend the capacity integer to be at least as wide as low and high.
+	capacityType := capacity.Type()
+	if low.Type().IntTypeWidth() > capacityType.IntTypeWidth() {
+		capacityType = low.Type()
+	}
+	if high.Type().IntTypeWidth() > capacityType.IntTypeWidth() {
+		capacityType = high.Type()
+	}
+	if max.Type().IntTypeWidth() > capacityType.IntTypeWidth() {
+		capacityType = max.Type()
+	}
+	if capacityType != capacity.Type() {
+		capacity = b.CreateZExt(capacity, capacityType, "")
+	}
+
+	// Extend low and high to be the same size as capacity.
+	if low.Type().IntTypeWidth() < capacityType.IntTypeWidth() {
+		if lowType.Info()&types.IsUnsigned != 0 {
+			low = b.CreateZExt(low, capacityType, "")
+		} else {
+			low = b.CreateSExt(low, capacityType, "")
+		}
+	}
+	if high.Type().IntTypeWidth() < capacityType.IntTypeWidth() {
+		if highType.Info()&types.IsUnsigned != 0 {
+			high = b.CreateZExt(high, capacityType, "")
+		} else {
+			high = b.CreateSExt(high, capacityType, "")
+		}
+	}
+	if max.Type().IntTypeWidth() < capacityType.IntTypeWidth() {
+		if maxType.Info()&types.IsUnsigned != 0 {
+			max = b.CreateZExt(max, capacityType, "")
+		} else {
+			max = b.CreateSExt(max, capacityType, "")
+		}
+	}
+
+	// Now do the bounds check: low > high || high > capacity
+	outOfBounds1 := b.CreateICmp(llvm.IntUGT, low, high, "slice.lowhigh")
+	outOfBounds2 := b.CreateICmp(llvm.IntUGT, high, max, "slice.highmax")
+	outOfBounds3 := b.CreateICmp(llvm.IntUGT, max, capacity, "slice.maxcap")
+	outOfBounds := b.CreateOr(outOfBounds1, outOfBounds2, "slice.lowmax")
+	outOfBounds = b.CreateOr(outOfBounds, outOfBounds3, "slice.lowcap")
+	b.createRuntimeAssert(outOfBounds, "slice", "slicePanic")
+}
+
+// createChanBoundsCheck creates a bounds check before creating a new channel to
+// check that the value is not too big for runtime.chanMake.
+func (b *builder) createChanBoundsCheck(elementSize uint64, bufSize llvm.Value, bufSizeType *types.Basic, pos token.Pos) {
+	if b.info.nobounds {
+		// The //go:nobounds pragma was added to the function to avoid bounds
+		// checking.
+		return
+	}
+
+	// Check whether the bufSize parameter must be cast to a wider integer for
+	// comparison.
+	if bufSize.Type().IntTypeWidth() < b.uintptrType.IntTypeWidth() {
+		if bufSizeType.Info()&types.IsUnsigned != 0 {
+			// Unsigned, so zero-extend to uint type.
+			bufSizeType = types.Typ[types.Uint]
+			bufSize = b.CreateZExt(bufSize, b.intType, "")
+		} else {
+			// Signed, so sign-extend to int type.
+			bufSizeType = types.Typ[types.Int]
+			bufSize = b.CreateSExt(bufSize, b.intType, "")
+		}
+	}
+
+	// Calculate (^uintptr(0)) >> 1, which is the max value that fits in an
+	// uintptr if uintptrs were signed.
+	maxBufSize := llvm.ConstLShr(llvm.ConstNot(llvm.ConstInt(b.uintptrType, 0, false)), llvm.ConstInt(b.uintptrType, 1, false))
+	if elementSize > maxBufSize.ZExtValue() {
+		b.addError(pos, fmt.Sprintf("channel element type is too big (%v bytes)", elementSize))
+		return
+	}
+	// Avoid divide-by-zero.
+	if elementSize == 0 {
+		elementSize = 1
+	}
+	// Make the maxBufSize actually the maximum allowed value (in number of
+	// elements in the channel buffer).
+	maxBufSize = llvm.ConstUDiv(maxBufSize, llvm.ConstInt(b.uintptrType, elementSize, false))
+
+	// Make sure maxBufSize has the same type as bufSize.
+	if maxBufSize.Type() != bufSize.Type() {
+		maxBufSize = llvm.ConstZExt(maxBufSize, bufSize.Type())
+	}
+
+	// Do the check for a too large (or negative) buffer size.
+	bufSizeTooBig := b.CreateICmp(llvm.IntUGE, bufSize, maxBufSize, "")
+	b.createRuntimeAssert(bufSizeTooBig, "chan", "chanMakePanic")
+}
+
+// createNilCheck checks whether the given pointer is nil, and panics if it is.
+// It has no effect in well-behaved programs, but makes sure no uncaught nil
+// pointer dereferences exist in valid Go code.
+func (b *builder) createNilCheck(inst ssa.Value, ptr llvm.Value, blockPrefix string) {
+	// Check whether we need to emit this check at all.
+	if !ptr.IsAGlobalValue().IsNil() {
+		return
+	}
+
+	switch inst := inst.(type) {
+	case *ssa.Alloc:
+		// An alloc is never nil.
+		return
+	case *ssa.IndexAddr:
+		// This pointer is the result of an index operation into a slice or
+		// array. Such slices/arrays are already bounds checked so the pointer
+		// must be a valid (non-nil) pointer. No nil checking is necessary.
+		return
+	case *ssa.Convert:
+		// This is a pointer that comes from a conversion from unsafe.Pointer.
+		// Don't do nil checking because this is unsafe code and the code should
+		// know what it is doing.
+		// Note: all *ssa.Convert instructions that result in a pointer must
+		// come from unsafe.Pointer. Testing here for unsafe.Pointer to be sure.
+		if inst.X.Type() == types.Typ[types.UnsafePointer] {
+			return
+		}
+	}
+
+	// Compare against nil.
+	// We previously used a hack to make sure this wouldn't break escape
+	// analysis, but this is not necessary anymore since
+	// https://reviews.llvm.org/D60047 has been merged.
+	nilptr := llvm.ConstPointerNull(ptr.Type())
+	isnil := b.CreateICmp(llvm.IntEQ, ptr, nilptr, "")
+
+	// Emit the nil check in IR.
+	b.createRuntimeAssert(isnil, blockPrefix, "nilPanic")
+}
+
+// createNegativeShiftCheck creates an assertion that panics if the given shift value is negative.
+// This function assumes that the shift value is signed.
+func (b *builder) createNegativeShiftCheck(shift llvm.Value) {
+	if b.info.nobounds {
+		// Function disabled bounds checking - skip shift check.
+		return
+	}
+
+	// isNegative = shift < 0
+	isNegative := b.CreateICmp(llvm.IntSLT, shift, llvm.ConstInt(shift.Type(), 0, false), "")
+	b.createRuntimeAssert(isNegative, "shift", "negativeShiftPanic")
+}
+
+// createRuntimeAssert is a common function to create a new branch on an assert
+// bool, calling an assert func if the assert value is true (1).
+func (b *builder) createRuntimeAssert(assert llvm.Value, blockPrefix, assertFunc string) {
+	// Check whether we can resolve this check at compile time.
+	if !assert.IsAConstantInt().IsNil() {
+		val := assert.ZExtValue()
+		if val == 0 {
+			// Everything is constant so the check does not have to be emitted
+			// in IR. This avoids emitting some redundant IR.
+			return
+		}
+	}
+
+	faultBlock := b.ctx.AddBasicBlock(b.llvmFn, blockPrefix+".throw")
+	nextBlock := b.ctx.AddBasicBlock(b.llvmFn, blockPrefix+".next")
+	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+
+	// Now branch to the out-of-bounds or the regular block.
+	b.CreateCondBr(assert, faultBlock, nextBlock)
+
+	// Fail: the assert triggered so panic.
+	b.SetInsertPointAtEnd(faultBlock)
+	b.createRuntimeCall(assertFunc, nil, "")
+	b.CreateUnreachable()
+
+	// Ok: assert didn't trigger so continue normally.
+	b.SetInsertPointAtEnd(nextBlock)
+}

compiler/atomic.go

@@ -0,0 +1,84 @@
+package compiler
+
+import (
+	"strings"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createAtomicOp lowers an atomic library call by lowering it as an LLVM atomic
+// operation. It returns the result of the operation and true if the call could
+// be lowered inline, and false otherwise.
+func (b *builder) createAtomicOp(call *ssa.CallCommon) (llvm.Value, bool) {
+	name := call.Value.(*ssa.Function).Name()
+	switch name {
+	case "AddInt32", "AddInt64", "AddUint32", "AddUint64", "AddUintptr":
+		ptr := b.getValue(call.Args[0])
+		val := b.getValue(call.Args[1])
+		oldVal := b.CreateAtomicRMW(llvm.AtomicRMWBinOpAdd, ptr, val, llvm.AtomicOrderingSequentiallyConsistent, true)
+		// Return the new value, not the original value returned by atomicrmw.
+		return b.CreateAdd(oldVal, val, ""), true
+	case "SwapInt32", "SwapInt64", "SwapUint32", "SwapUint64", "SwapUintptr", "SwapPointer":
+		ptr := b.getValue(call.Args[0])
+		val := b.getValue(call.Args[1])
+		isPointer := val.Type().TypeKind() == llvm.PointerTypeKind
+		if isPointer {
+			// atomicrmw only supports integers, so cast to an integer.
+			val = b.CreatePtrToInt(val, b.uintptrType, "")
+			ptr = b.CreateBitCast(ptr, llvm.PointerType(val.Type(), 0), "")
+		}
+		oldVal := b.CreateAtomicRMW(llvm.AtomicRMWBinOpXchg, ptr, val, llvm.AtomicOrderingSequentiallyConsistent, true)
+		if isPointer {
+			oldVal = b.CreateIntToPtr(oldVal, b.i8ptrType, "")
+		}
+		return oldVal, true
+	case "CompareAndSwapInt32", "CompareAndSwapInt64", "CompareAndSwapUint32", "CompareAndSwapUint64", "CompareAndSwapUintptr", "CompareAndSwapPointer":
+		ptr := b.getValue(call.Args[0])
+		old := b.getValue(call.Args[1])
+		newVal := b.getValue(call.Args[2])
+		if strings.HasSuffix(name, "64") {
+			arch := strings.Split(b.Triple, "-")[0]
+			if strings.HasPrefix(arch, "arm") && strings.HasSuffix(arch, "m") {
+				// Work around a bug in LLVM, at least LLVM 11:
+				// https://reviews.llvm.org/D95891
+				// Check for armv6m, armv7, armv7em, and perhaps others.
+				// See also: https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html
+				compareAndSwap := b.mod.NamedFunction("__sync_val_compare_and_swap_8")
+				if compareAndSwap.IsNil() {
+					// Declare the function if it isn't already declared.
+					i64Type := b.ctx.Int64Type()
+					fnType := llvm.FunctionType(i64Type, []llvm.Type{llvm.PointerType(i64Type, 0), i64Type, i64Type}, false)
+					compareAndSwap = llvm.AddFunction(b.mod, "__sync_val_compare_and_swap_8", fnType)
+				}
+				actualOldValue := b.CreateCall(compareAndSwap, []llvm.Value{ptr, old, newVal}, "")
+				// The __sync_val_compare_and_swap_8 function returns the old
+				// value. However, we shouldn't return the old value, we should
+				// return whether the compare/exchange was successful. This is
+				// easily done by comparing the returned (actual) old value with
+				// the expected old value passed to
+				// __sync_val_compare_and_swap_8.
+				swapped := b.CreateICmp(llvm.IntEQ, old, actualOldValue, "")
+				return swapped, true
+			}
+		}
+		tuple := b.CreateAtomicCmpXchg(ptr, old, newVal, llvm.AtomicOrderingSequentiallyConsistent, llvm.AtomicOrderingSequentiallyConsistent, true)
+		swapped := b.CreateExtractValue(tuple, 1, "")
+		return swapped, true
+	case "LoadInt32", "LoadInt64", "LoadUint32", "LoadUint64", "LoadUintptr", "LoadPointer":
+		ptr := b.getValue(call.Args[0])
+		val := b.CreateLoad(ptr, "")
+		val.SetOrdering(llvm.AtomicOrderingSequentiallyConsistent)
+		val.SetAlignment(b.targetData.PrefTypeAlignment(val.Type())) // required
+		return val, true
+	case "StoreInt32", "StoreInt64", "StoreUint32", "StoreUint64", "StoreUintptr", "StorePointer":
+		ptr := b.getValue(call.Args[0])
+		val := b.getValue(call.Args[1])
+		store := b.CreateStore(val, ptr)
+		store.SetOrdering(llvm.AtomicOrderingSequentiallyConsistent)
+		store.SetAlignment(b.targetData.PrefTypeAlignment(val.Type())) // required
+		return store, true
+	default:
+		return llvm.Value{}, false
+	}
+}

compiler/calls.go

@@ -1,8 +1,11 @@
 package compiler
 
 import (
-	"github.com/aykevl/go-llvm"
+	"go/types"
+	"strconv"
+
 	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
 )
 
 // For a description of the calling convention in prose, see:
@@ -10,58 +13,102 @@ import (
 
 // The maximum number of arguments that can be expanded from a single struct. If
 // a struct contains more fields, it is passed as a struct without expanding.
-const MaxFieldsPerParam = 3
+const maxFieldsPerParam = 3
 
-// Shortcut: create a call to runtime.<fnName> with the given arguments.
-func (c *Compiler) createRuntimeCall(fnName string, args []llvm.Value, name string) llvm.Value {
-	runtimePkg := c.ir.Program.ImportedPackage("runtime")
-	member := runtimePkg.Members[fnName]
-	if member == nil {
-		panic("trying to call runtime." + fnName)
-	}
-	fn := c.ir.GetFunction(member.(*ssa.Function))
-	if !fn.IsExported() {
-		args = append(args, llvm.Undef(c.i8ptrType)) // unused context parameter
-	}
-	return c.createCall(fn.LLVMFn, args, name)
+// paramInfo contains some information collected about a function parameter,
+// useful while declaring or defining a function.
+type paramInfo struct {
+	llvmType llvm.Type
+	name     string // name, possibly with suffixes for e.g. struct fields
+	flags    paramFlags
 }
 
-// Create a call to the given function with the arguments possibly expanded.
-func (c *Compiler) createCall(fn llvm.Value, args []llvm.Value, name string) llvm.Value {
+// paramFlags identifies parameter attributes for flags. Most importantly, it
+// determines which parameters are dereferenceable_or_null and which aren't.
+type paramFlags uint8
+
+const (
+	// Parameter may have the deferenceable_or_null attribute. This attribute
+	// cannot be applied to unsafe.Pointer and to the data pointer of slices.
+	paramIsDeferenceableOrNull = 1 << iota
+)
+
+// createCall creates a new call to runtime.<fnName> with the given arguments.
+func (b *builder) createRuntimeCall(fnName string, args []llvm.Value, name string) llvm.Value {
+	fn := b.program.ImportedPackage("runtime").Members[fnName].(*ssa.Function)
+	llvmFn := b.getFunction(fn)
+	if llvmFn.IsNil() {
+		panic("trying to call non-existent function: " + fn.RelString(nil))
+	}
+	args = append(args, llvm.Undef(b.i8ptrType))            // unused context parameter
+	args = append(args, llvm.ConstPointerNull(b.i8ptrType)) // coroutine handle
+	return b.createCall(llvmFn, args, name)
+}
+
+// createCall creates a call to the given function with the arguments possibly
+// expanded.
+func (b *builder) createCall(fn llvm.Value, args []llvm.Value, name string) llvm.Value {
 	expanded := make([]llvm.Value, 0, len(args))
 	for _, arg := range args {
-		fragments := c.expandFormalParam(arg)
+		fragments := b.expandFormalParam(arg)
 		expanded = append(expanded, fragments...)
 	}
-	return c.builder.CreateCall(fn, expanded, name)
+	return b.CreateCall(fn, expanded, name)
 }
 
 // Expand an argument type to a list that can be used in a function call
-// paramter list.
-func (c *Compiler) expandFormalParamType(t llvm.Type) []llvm.Type {
+// parameter list.
+func expandFormalParamType(t llvm.Type, name string, goType types.Type) []paramInfo {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		fields := c.flattenAggregateType(t)
-		if len(fields) <= MaxFieldsPerParam {
-			return fields
+		fieldInfos := flattenAggregateType(t, name, goType)
+		if len(fieldInfos) <= maxFieldsPerParam {
+			return fieldInfos
 		} else {
 			// failed to lower
-			return []llvm.Type{t}
 		}
-	default:
-		// TODO: split small arrays
-		return []llvm.Type{t}
+	}
+	// TODO: split small arrays
+	return []paramInfo{
+		{
+			llvmType: t,
+			name:     name,
+			flags:    getTypeFlags(goType),
+		},
 	}
 }
 
-// Equivalent of expandFormalParamType for parameter values.
-func (c *Compiler) expandFormalParam(v llvm.Value) []llvm.Value {
+// expandFormalParamOffsets returns a list of offsets from the start of an
+// object of type t after it would have been split up by expandFormalParam. This
+// is useful for debug information, where it is necessary to know the offset
+// from the start of the combined object.
+func (b *builder) expandFormalParamOffsets(t llvm.Type) []uint64 {
+	switch t.TypeKind() {
+	case llvm.StructTypeKind:
+		fields := b.flattenAggregateTypeOffsets(t)
+		if len(fields) <= maxFieldsPerParam {
+			return fields
+		} else {
+			// failed to lower
+			return []uint64{0}
+		}
+	default:
+		// TODO: split small arrays
+		return []uint64{0}
+	}
+}
+
+// expandFormalParam splits a formal param value into pieces, so it can be
+// passed directly as part of a function call. For example, it splits up small
+// structs into individual fields. It is the equivalent of expandFormalParamType
+// for parameter values.
+func (b *builder) expandFormalParam(v llvm.Value) []llvm.Value {
 	switch v.Type().TypeKind() {
 	case llvm.StructTypeKind:
-		fieldTypes := c.flattenAggregateType(v.Type())
-		if len(fieldTypes) <= MaxFieldsPerParam {
-			fields := c.flattenAggregate(v)
-			if len(fields) != len(fieldTypes) {
+		fieldInfos := flattenAggregateType(v.Type(), "", nil)
+		if len(fieldInfos) <= maxFieldsPerParam {
+			fields := b.flattenAggregate(v)
+			if len(fields) != len(fieldInfos) {
 				panic("type and value param lowering don't match")
 			}
 			return fields
@@ -77,29 +124,124 @@ func (c *Compiler) expandFormalParam(v llvm.Value) []llvm.Value {
 
 // Try to flatten a struct type to a list of types. Returns a 1-element slice
 // with the passed in type if this is not possible.
-func (c *Compiler) flattenAggregateType(t llvm.Type) []llvm.Type {
+func flattenAggregateType(t llvm.Type, name string, goType types.Type) []paramInfo {
+	typeFlags := getTypeFlags(goType)
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		fields := make([]llvm.Type, 0, t.StructElementTypesCount())
-		for _, subfield := range t.StructElementTypes() {
-			subfields := c.flattenAggregateType(subfield)
-			fields = append(fields, subfields...)
+		paramInfos := make([]paramInfo, 0, t.StructElementTypesCount())
+		for i, subfield := range t.StructElementTypes() {
+			suffix := strconv.Itoa(i)
+			if goType != nil {
+				// Try to come up with a good suffix for this struct field,
+				// depending on which Go type it's based on.
+				switch goType := goType.Underlying().(type) {
+				case *types.Interface:
+					suffix = []string{"typecode", "value"}[i]
+				case *types.Slice:
+					suffix = []string{"data", "len", "cap"}[i]
+				case *types.Struct:
+					suffix = goType.Field(i).Name()
+				case *types.Basic:
+					switch goType.Kind() {
+					case types.Complex64, types.Complex128:
+						suffix = []string{"r", "i"}[i]
+					case types.String:
+						suffix = []string{"data", "len"}[i]
+					}
+				case *types.Signature:
+					suffix = []string{"context", "funcptr"}[i]
+				}
+			}
+			subInfos := flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
+			for i := range subInfos {
+				subInfos[i].flags |= typeFlags
+			}
+			paramInfos = append(paramInfos, subInfos...)
 		}
-		return fields
+		return paramInfos
 	default:
-		return []llvm.Type{t}
+		return []paramInfo{
+			{
+				llvmType: t,
+				name:     name,
+				flags:    typeFlags,
+			},
+		}
 	}
 }
 
-// Break down a struct into its elementary types for argument passing. The value
-// equivalent of flattenAggregateType
-func (c *Compiler) flattenAggregate(v llvm.Value) []llvm.Value {
+// getTypeFlags returns the type flags for a given type. It will not recurse
+// into sub-types (such as in structs).
+func getTypeFlags(t types.Type) paramFlags {
+	if t == nil {
+		return 0
+	}
+	switch t.Underlying().(type) {
+	case *types.Pointer:
+		// Pointers in Go must either point to an object or be nil.
+		return paramIsDeferenceableOrNull
+	case *types.Chan, *types.Map:
+		// Channels and maps are implemented as pointers pointing to some
+		// object, and follow the same rules as *types.Pointer.
+		return paramIsDeferenceableOrNull
+	default:
+		return 0
+	}
+}
+
+// extractSubfield extracts a field from a struct, or returns null if this is
+// not a struct and thus no subfield can be obtained.
+func extractSubfield(t types.Type, field int) types.Type {
+	if t == nil {
+		return nil
+	}
+	switch t := t.Underlying().(type) {
+	case *types.Struct:
+		return t.Field(field).Type()
+	case *types.Interface, *types.Slice, *types.Basic, *types.Signature:
+		// These Go types are (sometimes) implemented as LLVM structs but can't
+		// really be split further up in Go (with the possible exception of
+		// complex numbers).
+		return nil
+	default:
+		// This should be unreachable.
+		panic("cannot split subfield: " + t.String())
+	}
+}
+
+// flattenAggregateTypeOffset returns the offsets from the start of an object of
+// type t if this object were flattened like in flattenAggregate. Used together
+// with flattenAggregate to know the start indices of each value in the
+// non-flattened object.
+//
+// Note: this is an implementation detail, use expandFormalParamOffsets instead.
+func (c *compilerContext) flattenAggregateTypeOffsets(t llvm.Type) []uint64 {
+	switch t.TypeKind() {
+	case llvm.StructTypeKind:
+		fields := make([]uint64, 0, t.StructElementTypesCount())
+		for fieldIndex, field := range t.StructElementTypes() {
+			suboffsets := c.flattenAggregateTypeOffsets(field)
+			offset := c.targetData.ElementOffset(t, fieldIndex)
+			for i := range suboffsets {
+				suboffsets[i] += offset
+			}
+			fields = append(fields, suboffsets...)
+		}
+		return fields
+	default:
+		return []uint64{0}
+	}
+}
+
+// flattenAggregate breaks down a struct into its elementary values for argument
+// passing. It is the value equivalent of flattenAggregateType
+func (b *builder) flattenAggregate(v llvm.Value) []llvm.Value {
 	switch v.Type().TypeKind() {
 	case llvm.StructTypeKind:
 		fields := make([]llvm.Value, 0, v.Type().StructElementTypesCount())
 		for i := range v.Type().StructElementTypes() {
-			subfield := c.builder.CreateExtractValue(v, i, "")
-			subfields := c.flattenAggregate(subfield)
+			subfield := b.CreateExtractValue(v, i, "")
+			subfields := b.flattenAggregate(subfield)
 			fields = append(fields, subfields...)
 		}
 		return fields
@@ -108,28 +250,29 @@ func (c *Compiler) flattenAggregate(v llvm.Value) []llvm.Value {
 	}
 }
 
-// Collapse a list of fields into its original value.
-func (c *Compiler) collapseFormalParam(t llvm.Type, fields []llvm.Value) llvm.Value {
-	param, remaining := c.collapseFormalParamInternal(t, fields)
+// collapseFormalParam combines an aggregate object back into the original
+// value. This is used to join multiple LLVM parameters into a single Go value
+// in the function entry block.
+func (b *builder) collapseFormalParam(t llvm.Type, fields []llvm.Value) llvm.Value {
+	param, remaining := b.collapseFormalParamInternal(t, fields)
 	if len(remaining) != 0 {
 		panic("failed to expand back all fields")
 	}
 	return param
 }
 
-// Returns (value, remainingFields). Used by collapseFormalParam.
-func (c *Compiler) collapseFormalParamInternal(t llvm.Type, fields []llvm.Value) (llvm.Value, []llvm.Value) {
+// collapseFormalParamInternal is an implementation detail of
+// collapseFormalParam: it works by recursing until there are no fields left.
+func (b *builder) collapseFormalParamInternal(t llvm.Type, fields []llvm.Value) (llvm.Value, []llvm.Value) {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		if len(c.flattenAggregateType(t)) <= MaxFieldsPerParam {
-			value, err := c.getZeroValue(t)
-			if err != nil {
-				panic("could not get zero value of struct: " + err.Error())
-			}
+		flattened := flattenAggregateType(t, "", nil)
+		if len(flattened) <= maxFieldsPerParam {
+			value := llvm.ConstNull(t)
 			for i, subtyp := range t.StructElementTypes() {
-				structField, remaining := c.collapseFormalParamInternal(subtyp, fields)
+				structField, remaining := b.collapseFormalParamInternal(subtyp, fields)
 				fields = remaining
-				value = c.builder.CreateInsertValue(value, structField, i, "")
+				value = b.CreateInsertValue(value, structField, i, "")
 			}
 			return value, fields
 		} else {

compiler/channel.go

@@ -0,0 +1,252 @@
+package compiler
+
+// This file lowers channel operations (make/send/recv/close) to runtime calls
+// or pseudo-operations that are lowered during goroutine lowering.
+
+import (
+	"go/types"
+
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+func (b *builder) createMakeChan(expr *ssa.MakeChan) llvm.Value {
+	elementSize := b.targetData.TypeAllocSize(b.getLLVMType(expr.Type().Underlying().(*types.Chan).Elem()))
+	elementSizeValue := llvm.ConstInt(b.uintptrType, elementSize, false)
+	bufSize := b.getValue(expr.Size)
+	b.createChanBoundsCheck(elementSize, bufSize, expr.Size.Type().Underlying().(*types.Basic), expr.Pos())
+	if bufSize.Type().IntTypeWidth() < b.uintptrType.IntTypeWidth() {
+		bufSize = b.CreateZExt(bufSize, b.uintptrType, "")
+	} else if bufSize.Type().IntTypeWidth() > b.uintptrType.IntTypeWidth() {
+		bufSize = b.CreateTrunc(bufSize, b.uintptrType, "")
+	}
+	return b.createRuntimeCall("chanMake", []llvm.Value{elementSizeValue, bufSize}, "")
+}
+
+// createChanSend emits a pseudo chan send operation. It is lowered to the
+// actual channel send operation during goroutine lowering.
+func (b *builder) createChanSend(instr *ssa.Send) {
+	ch := b.getValue(instr.Chan)
+	chanValue := b.getValue(instr.X)
+
+	// store value-to-send
+	valueType := b.getLLVMType(instr.X.Type())
+	valueAlloca, valueAllocaCast, valueAllocaSize := b.createTemporaryAlloca(valueType, "chan.value")
+	b.CreateStore(chanValue, valueAlloca)
+
+	// Allocate blockedlist buffer.
+	channelBlockedList := b.mod.GetTypeByName("runtime.channelBlockedList")
+	channelBlockedListAlloca, channelBlockedListAllocaCast, channelBlockedListAllocaSize := b.createTemporaryAlloca(channelBlockedList, "chan.blockedList")
+
+	// Do the send.
+	b.createRuntimeCall("chanSend", []llvm.Value{ch, valueAllocaCast, channelBlockedListAlloca}, "")
+
+	// End the lifetime of the allocas.
+	// This also works around a bug in CoroSplit, at least in LLVM 8:
+	// https://bugs.llvm.org/show_bug.cgi?id=41742
+	b.emitLifetimeEnd(channelBlockedListAllocaCast, channelBlockedListAllocaSize)
+	b.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
+}
+
+// createChanRecv emits a pseudo chan receive operation. It is lowered to the
+// actual channel receive operation during goroutine lowering.
+func (b *builder) createChanRecv(unop *ssa.UnOp) llvm.Value {
+	valueType := b.getLLVMType(unop.X.Type().Underlying().(*types.Chan).Elem())
+	ch := b.getValue(unop.X)
+
+	// Allocate memory to receive into.
+	valueAlloca, valueAllocaCast, valueAllocaSize := b.createTemporaryAlloca(valueType, "chan.value")
+
+	// Allocate blockedlist buffer.
+	channelBlockedList := b.mod.GetTypeByName("runtime.channelBlockedList")
+	channelBlockedListAlloca, channelBlockedListAllocaCast, channelBlockedListAllocaSize := b.createTemporaryAlloca(channelBlockedList, "chan.blockedList")
+
+	// Do the receive.
+	commaOk := b.createRuntimeCall("chanRecv", []llvm.Value{ch, valueAllocaCast, channelBlockedListAlloca}, "")
+	received := b.CreateLoad(valueAlloca, "chan.received")
+	b.emitLifetimeEnd(channelBlockedListAllocaCast, channelBlockedListAllocaSize)
+	b.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
+
+	if unop.CommaOk {
+		tuple := llvm.Undef(b.ctx.StructType([]llvm.Type{valueType, b.ctx.Int1Type()}, false))
+		tuple = b.CreateInsertValue(tuple, received, 0, "")
+		tuple = b.CreateInsertValue(tuple, commaOk, 1, "")
+		return tuple
+	} else {
+		return received
+	}
+}
+
+// createChanClose closes the given channel.
+func (b *builder) createChanClose(ch llvm.Value) {
+	b.createRuntimeCall("chanClose", []llvm.Value{ch}, "")
+}
+
+// createSelect emits all IR necessary for a select statements. That's a
+// non-trivial amount of code because select is very complex to implement.
+func (b *builder) createSelect(expr *ssa.Select) llvm.Value {
+	if len(expr.States) == 0 {
+		// Shortcuts for some simple selects.
+		llvmType := b.getLLVMType(expr.Type())
+		if expr.Blocking {
+			// Blocks forever:
+			//     select {}
+			b.createRuntimeCall("deadlock", nil, "")
+			return llvm.Undef(llvmType)
+		} else {
+			// No-op:
+			//     select {
+			//     default:
+			//     }
+			retval := llvm.Undef(llvmType)
+			retval = b.CreateInsertValue(retval, llvm.ConstInt(b.intType, 0xffffffffffffffff, true), 0, "")
+			return retval // {-1, false}
+		}
+	}
+
+	// This code create a (stack-allocated) slice containing all the select
+	// cases and then calls runtime.chanSelect to perform the actual select
+	// statement.
+	// Simple selects (blocking and with just one case) are already transformed
+	// into regular chan operations during SSA construction so we don't have to
+	// optimize such small selects.
+
+	// Go through all the cases. Create the selectStates slice and and
+	// determine the receive buffer size and alignment.
+	recvbufSize := uint64(0)
+	recvbufAlign := 0
+	hasReceives := false
+	var selectStates []llvm.Value
+	chanSelectStateType := b.getLLVMRuntimeType("chanSelectState")
+	for _, state := range expr.States {
+		ch := b.getValue(state.Chan)
+		selectState := llvm.ConstNull(chanSelectStateType)
+		selectState = b.CreateInsertValue(selectState, ch, 0, "")
+		switch state.Dir {
+		case types.RecvOnly:
+			// Make sure the receive buffer is big enough and has the correct alignment.
+			llvmType := b.getLLVMType(state.Chan.Type().Underlying().(*types.Chan).Elem())
+			if size := b.targetData.TypeAllocSize(llvmType); size > recvbufSize {
+				recvbufSize = size
+			}
+			if align := b.targetData.ABITypeAlignment(llvmType); align > recvbufAlign {
+				recvbufAlign = align
+			}
+			hasReceives = true
+		case types.SendOnly:
+			// Store this value in an alloca and put a pointer to this alloca
+			// in the send state.
+			sendValue := b.getValue(state.Send)
+			alloca := llvmutil.CreateEntryBlockAlloca(b.Builder, sendValue.Type(), "select.send.value")
+			b.CreateStore(sendValue, alloca)
+			ptr := b.CreateBitCast(alloca, b.i8ptrType, "")
+			selectState = b.CreateInsertValue(selectState, ptr, 1, "")
+		default:
+			panic("unreachable")
+		}
+		selectStates = append(selectStates, selectState)
+	}
+
+	// Create a receive buffer, where the received value will be stored.
+	recvbuf := llvm.Undef(b.i8ptrType)
+	if hasReceives {
+		allocaType := llvm.ArrayType(b.ctx.Int8Type(), int(recvbufSize))
+		recvbufAlloca, _, _ := b.createTemporaryAlloca(allocaType, "select.recvbuf.alloca")
+		recvbufAlloca.SetAlignment(recvbufAlign)
+		recvbuf = b.CreateGEP(recvbufAlloca, []llvm.Value{
+			llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+		}, "select.recvbuf")
+	}
+
+	// Create the states slice (allocated on the stack).
+	statesAllocaType := llvm.ArrayType(chanSelectStateType, len(selectStates))
+	statesAlloca, statesI8, statesSize := b.createTemporaryAlloca(statesAllocaType, "select.states.alloca")
+	for i, state := range selectStates {
+		// Set each slice element to the appropriate channel.
+		gep := b.CreateGEP(statesAlloca, []llvm.Value{
+			llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(b.ctx.Int32Type(), uint64(i), false),
+		}, "")
+		b.CreateStore(state, gep)
+	}
+	statesPtr := b.CreateGEP(statesAlloca, []llvm.Value{
+		llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+		llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+	}, "select.states")
+	statesLen := llvm.ConstInt(b.uintptrType, uint64(len(selectStates)), false)
+
+	// Do the select in the runtime.
+	var results llvm.Value
+	if expr.Blocking {
+		// Stack-allocate operation structures.
+		// If these were simply created as a slice, they would heap-allocate.
+		chBlockAllocaType := llvm.ArrayType(b.getLLVMRuntimeType("channelBlockedList"), len(selectStates))
+		chBlockAlloca, chBlockAllocaPtr, chBlockSize := b.createTemporaryAlloca(chBlockAllocaType, "select.block.alloca")
+		chBlockLen := llvm.ConstInt(b.uintptrType, uint64(len(selectStates)), false)
+		chBlockPtr := b.CreateGEP(chBlockAlloca, []llvm.Value{
+			llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+		}, "select.block")
+
+		results = b.createRuntimeCall("chanSelect", []llvm.Value{
+			recvbuf,
+			statesPtr, statesLen, statesLen, // []chanSelectState
+			chBlockPtr, chBlockLen, chBlockLen, // []channelBlockList
+		}, "select.result")
+
+		// Terminate the lifetime of the operation structures.
+		b.emitLifetimeEnd(chBlockAllocaPtr, chBlockSize)
+	} else {
+		results = b.createRuntimeCall("tryChanSelect", []llvm.Value{
+			recvbuf,
+			statesPtr, statesLen, statesLen, // []chanSelectState
+		}, "select.result")
+	}
+
+	// Terminate the lifetime of the states alloca.
+	b.emitLifetimeEnd(statesI8, statesSize)
+
+	// The result value does not include all the possible received values,
+	// because we can't load them in advance. Instead, the *ssa.Extract
+	// instruction will treat a *ssa.Select specially and load it there inline.
+	// Store the receive alloca in a sidetable until we hit this extract
+	// instruction.
+	if b.selectRecvBuf == nil {
+		b.selectRecvBuf = make(map[*ssa.Select]llvm.Value)
+	}
+	b.selectRecvBuf[expr] = recvbuf
+
+	return results
+}
+
+// getChanSelectResult returns the special values from a *ssa.Extract expression
+// when extracting a value from a select statement (*ssa.Select). Because
+// *ssa.Select cannot load all values in advance, it does this later in the
+// *ssa.Extract expression.
+func (b *builder) getChanSelectResult(expr *ssa.Extract) llvm.Value {
+	if expr.Index == 0 {
+		// index
+		value := b.getValue(expr.Tuple)
+		index := b.CreateExtractValue(value, expr.Index, "")
+		if index.Type().IntTypeWidth() < b.intType.IntTypeWidth() {
+			index = b.CreateSExt(index, b.intType, "")
+		}
+		return index
+	} else if expr.Index == 1 {
+		// comma-ok
+		value := b.getValue(expr.Tuple)
+		return b.CreateExtractValue(value, expr.Index, "")
+	} else {
+		// Select statements are (index, ok, ...) where ... is a number of
+		// received values, depending on how many receive statements there
+		// are. They are all combined into one alloca (because only one
+		// receive can proceed at a time) so we'll get that alloca, bitcast
+		// it to the correct type, and dereference it.
+		recvbuf := b.selectRecvBuf[expr.Tuple.(*ssa.Select)]
+		typ := llvm.PointerType(b.getLLVMType(expr.Type()), 0)
+		ptr := b.CreateBitCast(recvbuf, typ, "")
+		return b.CreateLoad(ptr, "")
+	}
+}

compiler/compiler_test.go

@@ -0,0 +1,161 @@
+package compiler
+
+import (
+	"flag"
+	"go/types"
+	"io/ioutil"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/loader"
+	"tinygo.org/x/go-llvm"
+)
+
+// Pass -update to go test to update the output of the test files.
+var flagUpdate = flag.Bool("update", false, "update tests based on test output")
+
+// Basic tests for the compiler. Build some Go files and compare the output with
+// the expected LLVM IR for regression testing.
+func TestCompiler(t *testing.T) {
+	// Check LLVM version.
+	llvmMajor, err := strconv.Atoi(strings.SplitN(llvm.Version, ".", 2)[0])
+	if err != nil {
+		t.Fatal("could not parse LLVM version:", llvm.Version)
+	}
+	if llvmMajor < 11 {
+		// It is likely this version needs to be bumped in the future.
+		// The goal is to at least test the LLVM version that's used by default
+		// in TinyGo and (if possible without too many workarounds) also some
+		// previous versions.
+		t.Skip("compiler tests require LLVM 11 or above, got LLVM ", llvm.Version)
+	}
+
+	target, err := compileopts.LoadTarget("i686--linux")
+	if err != nil {
+		t.Fatal("failed to load target:", err)
+	}
+	config := &compileopts.Config{
+		Options: &compileopts.Options{},
+		Target:  target,
+	}
+	compilerConfig := &Config{
+		Triple:             config.Triple(),
+		GOOS:               config.GOOS(),
+		GOARCH:             config.GOARCH(),
+		CodeModel:          config.CodeModel(),
+		RelocationModel:    config.RelocationModel(),
+		Scheduler:          config.Scheduler(),
+		FuncImplementation: config.FuncImplementation(),
+		AutomaticStackSize: config.AutomaticStackSize(),
+	}
+	machine, err := NewTargetMachine(compilerConfig)
+	if err != nil {
+		t.Fatal("failed to create target machine:", err)
+	}
+
+	tests := []string{
+		"basic.go",
+		"pointer.go",
+		"slice.go",
+		"string.go",
+		"float.go",
+		"interface.go",
+	}
+
+	for _, testCase := range tests {
+		t.Run(testCase, func(t *testing.T) {
+			// Load entire program AST into memory.
+			lprogram, err := loader.Load(config, []string{"./testdata/" + testCase}, config.ClangHeaders, types.Config{
+				Sizes: Sizes(machine),
+			})
+			if err != nil {
+				t.Fatal("failed to create target machine:", err)
+			}
+			err = lprogram.Parse()
+			if err != nil {
+				t.Fatalf("could not parse test case %s: %s", testCase, err)
+			}
+
+			// Compile AST to IR.
+			program := lprogram.LoadSSA()
+			pkg := lprogram.MainPkg()
+			mod, errs := CompilePackage(testCase, pkg, program.Package(pkg.Pkg), machine, compilerConfig, false)
+			if errs != nil {
+				for _, err := range errs {
+					t.Log("error:", err)
+				}
+				return
+			}
+
+			// Optimize IR a little.
+			funcPasses := llvm.NewFunctionPassManagerForModule(mod)
+			defer funcPasses.Dispose()
+			funcPasses.AddInstructionCombiningPass()
+			funcPasses.InitializeFunc()
+			for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+				funcPasses.RunFunc(fn)
+			}
+			funcPasses.FinalizeFunc()
+
+			outfile := "./testdata/" + testCase[:len(testCase)-3] + ".ll"
+
+			// Update test if needed. Do not check the result.
+			if *flagUpdate {
+				err := ioutil.WriteFile(outfile, []byte(mod.String()), 0666)
+				if err != nil {
+					t.Error("failed to write updated output file:", err)
+				}
+				return
+			}
+
+			expected, err := ioutil.ReadFile(outfile)
+			if err != nil {
+				t.Fatal("failed to read golden file:", err)
+			}
+
+			if !fuzzyEqualIR(mod.String(), string(expected)) {
+				t.Errorf("output does not match expected output:\n%s", mod.String())
+			}
+		})
+	}
+}
+
+// fuzzyEqualIR returns true if the two LLVM IR strings passed in are roughly
+// equal. That means, only relevant lines are compared (excluding comments
+// etc.).
+func fuzzyEqualIR(s1, s2 string) bool {
+	lines1 := filterIrrelevantIRLines(strings.Split(s1, "\n"))
+	lines2 := filterIrrelevantIRLines(strings.Split(s2, "\n"))
+	if len(lines1) != len(lines2) {
+		return false
+	}
+	for i, line1 := range lines1 {
+		line2 := lines2[i]
+		if line1 != line2 {
+			return false
+		}
+	}
+
+	return true
+}
+
+// filterIrrelevantIRLines removes lines from the input slice of strings that
+// are not relevant in comparing IR. For example, empty lines and comments are
+// stripped out.
+func filterIrrelevantIRLines(lines []string) []string {
+	var out []string
+	for _, line := range lines {
+		line = strings.Split(line, ";")[0]    // strip out comments/info
+		line = strings.TrimRight(line, "\r ") // drop '\r' on Windows and remove trailing spaces from comments
+		if line == "" {
+			continue
+		}
+		if strings.HasPrefix(line, "source_filename = ") {
+			continue
+		}
+		out = append(out, line)
+	}
+	return out
+}

compiler/defer.go

@@ -14,82 +14,110 @@ package compiler
 //     frames.
 
 import (
-	"github.com/aykevl/go-llvm"
-	"github.com/aykevl/tinygo/ir"
+	"go/types"
+
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
 )
 
 // deferInitFunc sets up this function for future deferred calls. It must be
 // called from within the entry block when this function contains deferred
 // calls.
-func (c *Compiler) deferInitFunc(frame *Frame) {
+func (b *builder) deferInitFunc() {
 	// Some setup.
-	frame.deferFuncs = make(map[*ir.Function]int)
-	frame.deferInvokeFuncs = make(map[string]int)
-	frame.deferClosureFuncs = make(map[*ir.Function]int)
+	b.deferFuncs = make(map[*ssa.Function]int)
+	b.deferInvokeFuncs = make(map[string]int)
+	b.deferClosureFuncs = make(map[*ssa.Function]int)
+	b.deferExprFuncs = make(map[ssa.Value]int)
+	b.deferBuiltinFuncs = make(map[ssa.Value]deferBuiltin)
 
 	// Create defer list pointer.
-	deferType := llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)
-	frame.deferPtr = c.builder.CreateAlloca(deferType, "deferPtr")
-	c.builder.CreateStore(llvm.ConstPointerNull(deferType), frame.deferPtr)
+	deferType := llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)
+	b.deferPtr = b.CreateAlloca(deferType, "deferPtr")
+	b.CreateStore(llvm.ConstPointerNull(deferType), b.deferPtr)
 }
 
-// emitDefer emits a single defer instruction, to be run when this function
+// isInLoop checks if there is a path from a basic block to itself.
+func isInLoop(start *ssa.BasicBlock) bool {
+	// Use a breadth-first search to scan backwards through the block graph.
+	queue := []*ssa.BasicBlock{start}
+	checked := map[*ssa.BasicBlock]struct{}{}
+
+	for len(queue) > 0 {
+		// pop a block off of the queue
+		block := queue[len(queue)-1]
+		queue = queue[:len(queue)-1]
+
+		// Search through predecessors.
+		// Searching backwards means that this is pretty fast when the block is close to the start of the function.
+		// Defers are often placed near the start of the function.
+		for _, pred := range block.Preds {
+			if pred == start {
+				// cycle found
+				return true
+			}
+
+			if _, ok := checked[pred]; ok {
+				// block already checked
+				continue
+			}
+
+			// add to queue and checked map
+			queue = append(queue, pred)
+			checked[pred] = struct{}{}
+		}
+	}
+
+	return false
+}
+
+// createDefer emits a single defer instruction, to be run when this function
 // returns.
-func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
+func (b *builder) createDefer(instr *ssa.Defer) {
 	// The pointer to the previous defer struct, which we will replace to
 	// make a linked list.
-	next := c.builder.CreateLoad(frame.deferPtr, "defer.next")
+	next := b.CreateLoad(b.deferPtr, "defer.next")
 
 	var values []llvm.Value
-	valueTypes := []llvm.Type{c.uintptrType, next.Type()}
+	valueTypes := []llvm.Type{b.uintptrType, next.Type()}
 	if instr.Call.IsInvoke() {
 		// Method call on an interface.
 
 		// Get callback type number.
 		methodName := instr.Call.Method.FullName()
-		if _, ok := frame.deferInvokeFuncs[methodName]; !ok {
-			frame.deferInvokeFuncs[methodName] = len(frame.allDeferFuncs)
-			frame.allDeferFuncs = append(frame.allDeferFuncs, &instr.Call)
+		if _, ok := b.deferInvokeFuncs[methodName]; !ok {
+			b.deferInvokeFuncs[methodName] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, &instr.Call)
 		}
-		callback := llvm.ConstInt(c.uintptrType, uint64(frame.deferInvokeFuncs[methodName]), false)
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferInvokeFuncs[methodName]), false)
 
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields, followed by the call parameters).
-		itf, err := c.parseExpr(frame, instr.Call.Value) // interface
-		if err != nil {
-			return err
-		}
-		receiverValue := c.builder.CreateExtractValue(itf, 1, "invoke.func.receiver")
-		values = []llvm.Value{callback, next, receiverValue}
-		valueTypes = append(valueTypes, c.i8ptrType)
+		itf := b.getValue(instr.Call.Value) // interface
+		typecode := b.CreateExtractValue(itf, 0, "invoke.func.typecode")
+		receiverValue := b.CreateExtractValue(itf, 1, "invoke.func.receiver")
+		values = []llvm.Value{callback, next, typecode, receiverValue}
+		valueTypes = append(valueTypes, b.uintptrType, b.i8ptrType)
 		for _, arg := range instr.Call.Args {
-			val, err := c.parseExpr(frame, arg)
-			if err != nil {
-				return err
-			}
+			val := b.getValue(arg)
 			values = append(values, val)
 			valueTypes = append(valueTypes, val.Type())
 		}
 
 	} else if callee, ok := instr.Call.Value.(*ssa.Function); ok {
 		// Regular function call.
-		fn := c.ir.GetFunction(callee)
-
-		if _, ok := frame.deferFuncs[fn]; !ok {
-			frame.deferFuncs[fn] = len(frame.allDeferFuncs)
-			frame.allDeferFuncs = append(frame.allDeferFuncs, fn)
+		if _, ok := b.deferFuncs[callee]; !ok {
+			b.deferFuncs[callee] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, callee)
 		}
-		callback := llvm.ConstInt(c.uintptrType, uint64(frame.deferFuncs[fn]), false)
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferFuncs[callee]), false)
 
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields).
 		values = []llvm.Value{callback, next}
 		for _, param := range instr.Call.Args {
-			llvmParam, err := c.parseExpr(frame, param)
-			if err != nil {
-				return err
-			}
+			llvmParam := b.getValue(param)
 			values = append(values, llvmParam)
 			valueTypes = append(valueTypes, llvmParam.Type())
 		}
@@ -101,61 +129,109 @@ func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
 		// pointer.
 		// TODO: ignore this closure entirely and put pointers to the free
 		// variables directly in the defer struct, avoiding a memory allocation.
-		closure, err := c.parseExpr(frame, instr.Call.Value)
-		if err != nil {
-			return err
-		}
-		context := c.builder.CreateExtractValue(closure, 0, "")
+		closure := b.getValue(instr.Call.Value)
+		context := b.CreateExtractValue(closure, 0, "")
 
 		// Get the callback number.
-		fn := c.ir.GetFunction(makeClosure.Fn.(*ssa.Function))
-		if _, ok := frame.deferClosureFuncs[fn]; !ok {
-			frame.deferClosureFuncs[fn] = len(frame.allDeferFuncs)
-			frame.allDeferFuncs = append(frame.allDeferFuncs, makeClosure)
+		fn := makeClosure.Fn.(*ssa.Function)
+		if _, ok := b.deferClosureFuncs[fn]; !ok {
+			b.deferClosureFuncs[fn] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, makeClosure)
 		}
-		callback := llvm.ConstInt(c.uintptrType, uint64(frame.deferClosureFuncs[fn]), false)
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferClosureFuncs[fn]), false)
 
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields, followed by all parameters including the
 		// context pointer).
 		values = []llvm.Value{callback, next}
 		for _, param := range instr.Call.Args {
-			llvmParam, err := c.parseExpr(frame, param)
-			if err != nil {
-				return err
-			}
+			llvmParam := b.getValue(param)
 			values = append(values, llvmParam)
 			valueTypes = append(valueTypes, llvmParam.Type())
 		}
 		values = append(values, context)
 		valueTypes = append(valueTypes, context.Type())
 
+	} else if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
+		var argTypes []types.Type
+		var argValues []llvm.Value
+		for _, arg := range instr.Call.Args {
+			argTypes = append(argTypes, arg.Type())
+			argValues = append(argValues, b.getValue(arg))
+		}
+
+		if _, ok := b.deferBuiltinFuncs[instr.Call.Value]; !ok {
+			b.deferBuiltinFuncs[instr.Call.Value] = deferBuiltin{
+				callName: builtin.Name(),
+				pos:      builtin.Pos(),
+				argTypes: argTypes,
+				callback: len(b.allDeferFuncs),
+			}
+			b.allDeferFuncs = append(b.allDeferFuncs, instr.Call.Value)
+		}
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferBuiltinFuncs[instr.Call.Value].callback), false)
+
+		// Collect all values to be put in the struct (starting with
+		// runtime._defer fields).
+		values = []llvm.Value{callback, next}
+		for _, param := range argValues {
+			values = append(values, param)
+			valueTypes = append(valueTypes, param.Type())
+		}
+
 	} else {
-		return c.makeError(instr.Pos(), "todo: defer on uncommon function call type")
+		funcValue := b.getValue(instr.Call.Value)
+
+		if _, ok := b.deferExprFuncs[instr.Call.Value]; !ok {
+			b.deferExprFuncs[instr.Call.Value] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, &instr.Call)
+		}
+
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferExprFuncs[instr.Call.Value]), false)
+
+		// Collect all values to be put in the struct (starting with
+		// runtime._defer fields, followed by all parameters including the
+		// context pointer).
+		values = []llvm.Value{callback, next, funcValue}
+		valueTypes = append(valueTypes, funcValue.Type())
+		for _, param := range instr.Call.Args {
+			llvmParam := b.getValue(param)
+			values = append(values, llvmParam)
+			valueTypes = append(valueTypes, llvmParam.Type())
+		}
 	}
 
 	// Make a struct out of the collected values to put in the defer frame.
-	deferFrameType := c.ctx.StructType(valueTypes, false)
-	deferFrame, err := c.getZeroValue(deferFrameType)
-	if err != nil {
-		return err
-	}
+	deferFrameType := b.ctx.StructType(valueTypes, false)
+	deferFrame := llvm.ConstNull(deferFrameType)
 	for i, value := range values {
-		deferFrame = c.builder.CreateInsertValue(deferFrame, value, i, "")
+		deferFrame = b.CreateInsertValue(deferFrame, value, i, "")
 	}
 
-	// Put this struct in an alloca.
-	alloca := c.builder.CreateAlloca(deferFrameType, "defer.alloca")
-	c.builder.CreateStore(deferFrame, alloca)
+	// Put this struct in an allocation.
+	var alloca llvm.Value
+	if !isInLoop(instr.Block()) {
+		// This can safely use a stack allocation.
+		alloca = llvmutil.CreateEntryBlockAlloca(b.Builder, deferFrameType, "defer.alloca")
+	} else {
+		// This may be hit a variable number of times, so use a heap allocation.
+		size := b.targetData.TypeAllocSize(deferFrameType)
+		sizeValue := llvm.ConstInt(b.uintptrType, size, false)
+		allocCall := b.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "defer.alloc.call")
+		alloca = b.CreateBitCast(allocCall, llvm.PointerType(deferFrameType, 0), "defer.alloc")
+	}
+	if b.NeedsStackObjects {
+		b.trackPointer(alloca)
+	}
+	b.CreateStore(deferFrame, alloca)
 
 	// Push it on top of the linked list by replacing deferPtr.
-	allocaCast := c.builder.CreateBitCast(alloca, next.Type(), "defer.alloca.cast")
-	c.builder.CreateStore(allocaCast, frame.deferPtr)
-	return nil
+	allocaCast := b.CreateBitCast(alloca, next.Type(), "defer.alloca.cast")
+	b.CreateStore(allocaCast, b.deferPtr)
 }
 
-// emitRunDefers emits code to run all deferred functions.
-func (c *Compiler) emitRunDefers(frame *Frame) error {
+// createRunDefers emits code to run all deferred functions.
+func (b *builder) createRunDefers() {
 	// Add a loop like the following:
 	//     for stack != nil {
 	//         _stack := stack
@@ -172,158 +248,208 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 	//     }
 
 	// Create loop.
-	loophead := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.loophead")
-	loop := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.loop")
-	unreachable := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.default")
-	end := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.end")
-	c.builder.CreateBr(loophead)
+	loophead := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.loophead")
+	loop := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.loop")
+	unreachable := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.default")
+	end := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.end")
+	b.CreateBr(loophead)
 
 	// Create loop head:
 	//     for stack != nil {
-	c.builder.SetInsertPointAtEnd(loophead)
-	deferData := c.builder.CreateLoad(frame.deferPtr, "")
-	stackIsNil := c.builder.CreateICmp(llvm.IntEQ, deferData, llvm.ConstPointerNull(deferData.Type()), "stackIsNil")
-	c.builder.CreateCondBr(stackIsNil, end, loop)
+	b.SetInsertPointAtEnd(loophead)
+	deferData := b.CreateLoad(b.deferPtr, "")
+	stackIsNil := b.CreateICmp(llvm.IntEQ, deferData, llvm.ConstPointerNull(deferData.Type()), "stackIsNil")
+	b.CreateCondBr(stackIsNil, end, loop)
 
 	// Create loop body:
 	//     _stack := stack
 	//     stack = stack.next
 	//     switch stack.callback {
-	c.builder.SetInsertPointAtEnd(loop)
-	nextStackGEP := c.builder.CreateGEP(deferData, []llvm.Value{
-		llvm.ConstInt(c.ctx.Int32Type(), 0, false),
-		llvm.ConstInt(c.ctx.Int32Type(), 1, false), // .next field
+	b.SetInsertPointAtEnd(loop)
+	nextStackGEP := b.CreateInBoundsGEP(deferData, []llvm.Value{
+		llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+		llvm.ConstInt(b.ctx.Int32Type(), 1, false), // .next field
 	}, "stack.next.gep")
-	nextStack := c.builder.CreateLoad(nextStackGEP, "stack.next")
-	c.builder.CreateStore(nextStack, frame.deferPtr)
-	gep := c.builder.CreateGEP(deferData, []llvm.Value{
-		llvm.ConstInt(c.ctx.Int32Type(), 0, false),
-		llvm.ConstInt(c.ctx.Int32Type(), 0, false), // .callback field
+	nextStack := b.CreateLoad(nextStackGEP, "stack.next")
+	b.CreateStore(nextStack, b.deferPtr)
+	gep := b.CreateInBoundsGEP(deferData, []llvm.Value{
+		llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+		llvm.ConstInt(b.ctx.Int32Type(), 0, false), // .callback field
 	}, "callback.gep")
-	callback := c.builder.CreateLoad(gep, "callback")
-	sw := c.builder.CreateSwitch(callback, unreachable, len(frame.allDeferFuncs))
+	callback := b.CreateLoad(gep, "callback")
+	sw := b.CreateSwitch(callback, unreachable, len(b.allDeferFuncs))
 
-	for i, callback := range frame.allDeferFuncs {
+	for i, callback := range b.allDeferFuncs {
 		// Create switch case, for example:
 		//     case 0:
 		//         // run first deferred call
-		block := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.callback")
-		sw.AddCase(llvm.ConstInt(c.uintptrType, uint64(i), false), block)
-		c.builder.SetInsertPointAtEnd(block)
+		block := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.callback")
+		sw.AddCase(llvm.ConstInt(b.uintptrType, uint64(i), false), block)
+		b.SetInsertPointAtEnd(block)
 		switch callback := callback.(type) {
 		case *ssa.CallCommon:
-			// Call on an interface value.
-			if !callback.IsInvoke() {
-				panic("expected an invoke call, not a direct call")
-			}
+			// Call on an value or interface value.
 
 			// Get the real defer struct type and cast to it.
-			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0), c.i8ptrType}
-			for _, arg := range callback.Args {
-				llvmType, err := c.getLLVMType(arg.Type())
-				if err != nil {
-					return err
-				}
-				valueTypes = append(valueTypes, llvmType)
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
+
+			if !callback.IsInvoke() {
+				//Expect funcValue to be passed through the defer frame.
+				valueTypes = append(valueTypes, b.getFuncType(callback.Signature()))
+			} else {
+				//Expect typecode
+				valueTypes = append(valueTypes, b.uintptrType, b.i8ptrType)
 			}
-			deferFrameType := c.ctx.StructType(valueTypes, false)
-			deferFramePtr := c.builder.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
+
+			for _, arg := range callback.Args {
+				valueTypes = append(valueTypes, b.getLLVMType(arg.Type()))
+			}
+
+			deferFrameType := b.ctx.StructType(valueTypes, false)
+			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
 
 			// Extract the params from the struct (including receiver).
 			forwardParams := []llvm.Value{}
-			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
+			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
 			for i := 2; i < len(valueTypes); i++ {
-				gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "gep")
-				forwardParam := c.builder.CreateLoad(gep, "param")
+				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i), false)}, "gep")
+				forwardParam := b.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
 			}
 
-			// Add the context parameter. An interface call cannot also be a
-			// closure but we have to supply the parameter anyway for platforms
-			// with a strict calling convention.
-			forwardParams = append(forwardParams, llvm.Undef(c.i8ptrType))
+			var fnPtr llvm.Value
 
-			fnPtr, _, err := c.getInvokeCall(frame, callback)
-			if err != nil {
-				return err
+			if !callback.IsInvoke() {
+				// Isolate the func value.
+				funcValue := forwardParams[0]
+				forwardParams = forwardParams[1:]
+
+				//Get function pointer and context
+				fp, context := b.decodeFuncValue(funcValue, callback.Signature())
+				fnPtr = fp
+
+				//Pass context
+				forwardParams = append(forwardParams, context)
+			} else {
+				// Isolate the typecode.
+				typecode := forwardParams[0]
+				forwardParams = forwardParams[1:]
+				fnPtr = b.getInvokePtr(callback, typecode)
+
+				// Add the context parameter. An interface call cannot also be a
+				// closure but we have to supply the parameter anyway for platforms
+				// with a strict calling convention.
+				forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
 			}
-			c.createCall(fnPtr, forwardParams, "")
 
-		case *ir.Function:
+			// Parent coroutine handle.
+			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
+
+			b.createCall(fnPtr, forwardParams, "")
+
+		case *ssa.Function:
 			// Direct call.
 
 			// Get the real defer struct type and cast to it.
-			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)}
-			for _, param := range callback.Params {
-				llvmType, err := c.getLLVMType(param.Type())
-				if err != nil {
-					return err
-				}
-				valueTypes = append(valueTypes, llvmType)
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
+			for _, param := range getParams(callback.Signature) {
+				valueTypes = append(valueTypes, b.getLLVMType(param.Type()))
 			}
-			deferFrameType := c.ctx.StructType(valueTypes, false)
-			deferFramePtr := c.builder.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
+			deferFrameType := b.ctx.StructType(valueTypes, false)
+			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
 
 			// Extract the params from the struct.
 			forwardParams := []llvm.Value{}
-			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
-			for i := range callback.Params {
-				gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i+2), false)}, "gep")
-				forwardParam := c.builder.CreateLoad(gep, "param")
+			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
+			for i := range getParams(callback.Signature) {
+				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i+2), false)}, "gep")
+				forwardParam := b.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
 			}
 
-			// Add the context parameter. We know it is ignored by the receiving
-			// function, but we have to pass one anyway.
-			forwardParams = append(forwardParams, llvm.Undef(c.i8ptrType))
+			// Plain TinyGo functions add some extra parameters to implement async functionality and function recievers.
+			// These parameters should not be supplied when calling into an external C/ASM function.
+			if !b.getFunctionInfo(callback).exported {
+				// Add the context parameter. We know it is ignored by the receiving
+				// function, but we have to pass one anyway.
+				forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
+
+				// Parent coroutine handle.
+				forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
+			}
 
 			// Call real function.
-			c.createCall(callback.LLVMFn, forwardParams, "")
+			b.createCall(b.getFunction(callback), forwardParams, "")
 
 		case *ssa.MakeClosure:
 			// Get the real defer struct type and cast to it.
-			fn := c.ir.GetFunction(callback.Fn.(*ssa.Function))
-			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)}
+			fn := callback.Fn.(*ssa.Function)
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
 			params := fn.Signature.Params()
 			for i := 0; i < params.Len(); i++ {
-				llvmType, err := c.getLLVMType(params.At(i).Type())
-				if err != nil {
-					return err
-				}
-				valueTypes = append(valueTypes, llvmType)
+				valueTypes = append(valueTypes, b.getLLVMType(params.At(i).Type()))
 			}
-			valueTypes = append(valueTypes, c.i8ptrType) // closure
-			deferFrameType := c.ctx.StructType(valueTypes, false)
-			deferFramePtr := c.builder.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
+			valueTypes = append(valueTypes, b.i8ptrType) // closure
+			deferFrameType := b.ctx.StructType(valueTypes, false)
+			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
 
 			// Extract the params from the struct.
 			forwardParams := []llvm.Value{}
-			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
+			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
 			for i := 2; i < len(valueTypes); i++ {
-				gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "")
-				forwardParam := c.builder.CreateLoad(gep, "param")
+				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i), false)}, "")
+				forwardParam := b.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
 			}
 
-			// Call deferred function.
-			c.createCall(fn.LLVMFn, forwardParams, "")
+			// Parent coroutine handle.
+			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
 
+			// Call deferred function.
+			b.createCall(b.getFunction(fn), forwardParams, "")
+		case *ssa.Builtin:
+			db := b.deferBuiltinFuncs[callback]
+
+			//Get parameter types
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
+
+			//Get signature from call results
+			params := callback.Type().Underlying().(*types.Signature).Params()
+			for i := 0; i < params.Len(); i++ {
+				valueTypes = append(valueTypes, b.getLLVMType(params.At(i).Type()))
+			}
+
+			deferFrameType := b.ctx.StructType(valueTypes, false)
+			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
+
+			// Extract the params from the struct.
+			var argValues []llvm.Value
+			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
+			for i := 0; i < params.Len(); i++ {
+				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i+2), false)}, "gep")
+				forwardParam := b.CreateLoad(gep, "param")
+				argValues = append(argValues, forwardParam)
+			}
+
+			_, err := b.createBuiltin(db.argTypes, argValues, db.callName, db.pos)
+			if err != nil {
+				b.diagnostics = append(b.diagnostics, err)
+			}
 		default:
 			panic("unknown deferred function type")
 		}
 
 		// Branch back to the start of the loop.
-		c.builder.CreateBr(loophead)
+		b.CreateBr(loophead)
 	}
 
 	// Create default unreachable block:
 	//     default:
 	//         unreachable
 	//     }
-	c.builder.SetInsertPointAtEnd(unreachable)
-	c.builder.CreateUnreachable()
+	b.SetInsertPointAtEnd(unreachable)
+	b.CreateUnreachable()
 
 	// End of loop.
-	c.builder.SetInsertPointAtEnd(end)
-	return nil
+	b.SetInsertPointAtEnd(end)
 }

compiler/errors.go

@@ -1,14 +1,64 @@
 package compiler
 
+// This file contains some utility functions related to error handling.
+
 import (
+	"go/scanner"
 	"go/token"
 	"go/types"
+	"path/filepath"
+
+	"tinygo.org/x/go-llvm"
 )
 
-func (c *Compiler) makeError(pos token.Pos, msg string) types.Error {
+// makeError makes it easy to create an error from a token.Pos with a message.
+func (c *compilerContext) makeError(pos token.Pos, msg string) types.Error {
 	return types.Error{
-		Fset: c.ir.Program.Fset,
+		Fset: c.program.Fset,
 		Pos:  pos,
 		Msg:  msg,
 	}
 }
+
+func (c *compilerContext) addError(pos token.Pos, msg string) {
+	c.diagnostics = append(c.diagnostics, c.makeError(pos, msg))
+}
+
+// errorAt returns an error value at the location of the instruction.
+// The location information may not be complete as it depends on debug
+// information in the IR.
+func errorAt(inst llvm.Value, msg string) scanner.Error {
+	return scanner.Error{
+		Pos: getPosition(inst),
+		Msg: msg,
+	}
+}
+
+// getPosition returns the position information for the given value, as far as
+// it is available.
+func getPosition(val llvm.Value) token.Position {
+	if !val.IsAInstruction().IsNil() {
+		loc := val.InstructionDebugLoc()
+		if loc.IsNil() {
+			return token.Position{}
+		}
+		file := loc.LocationScope().ScopeFile()
+		return token.Position{
+			Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+			Line:     int(loc.LocationLine()),
+			Column:   int(loc.LocationColumn()),
+		}
+	} else if !val.IsAFunction().IsNil() {
+		loc := val.Subprogram()
+		if loc.IsNil() {
+			return token.Position{}
+		}
+		file := loc.ScopeFile()
+		return token.Position{
+			Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+			Line:     int(loc.SubprogramLine()),
+		}
+	} else {
+		return token.Position{}
+	}
+}

compiler/func.go

@@ -0,0 +1,167 @@
+package compiler
+
+// This file implements function values and closures. It may need some lowering
+// in a later step, see func-lowering.go.
+
+import (
+	"go/types"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createFuncValue creates a function value from a raw function pointer with no
+// context.
+func (b *builder) createFuncValue(funcPtr, context llvm.Value, sig *types.Signature) llvm.Value {
+	return b.compilerContext.createFuncValue(b.Builder, funcPtr, context, sig)
+}
+
+// createFuncValue creates a function value from a raw function pointer with no
+// context.
+func (c *compilerContext) createFuncValue(builder llvm.Builder, funcPtr, context llvm.Value, sig *types.Signature) llvm.Value {
+	var funcValueScalar llvm.Value
+	switch c.FuncImplementation {
+	case "doubleword":
+		// Closure is: {context, function pointer}
+		funcValueScalar = funcPtr
+	case "switch":
+		sigGlobal := c.getTypeCode(sig)
+		funcValueWithSignatureGlobalName := funcPtr.Name() + "$withSignature"
+		funcValueWithSignatureGlobal := c.mod.NamedGlobal(funcValueWithSignatureGlobalName)
+		if funcValueWithSignatureGlobal.IsNil() {
+			funcValueWithSignatureType := c.getLLVMRuntimeType("funcValueWithSignature")
+			funcValueWithSignature := llvm.ConstNamedStruct(funcValueWithSignatureType, []llvm.Value{
+				llvm.ConstPtrToInt(funcPtr, c.uintptrType),
+				sigGlobal,
+			})
+			funcValueWithSignatureGlobal = llvm.AddGlobal(c.mod, funcValueWithSignatureType, funcValueWithSignatureGlobalName)
+			funcValueWithSignatureGlobal.SetInitializer(funcValueWithSignature)
+			funcValueWithSignatureGlobal.SetGlobalConstant(true)
+			funcValueWithSignatureGlobal.SetLinkage(llvm.LinkOnceODRLinkage)
+		}
+		funcValueScalar = llvm.ConstPtrToInt(funcValueWithSignatureGlobal, c.uintptrType)
+	default:
+		panic("unimplemented func value variant")
+	}
+	funcValueType := c.getFuncType(sig)
+	funcValue := llvm.Undef(funcValueType)
+	funcValue = builder.CreateInsertValue(funcValue, context, 0, "")
+	funcValue = builder.CreateInsertValue(funcValue, funcValueScalar, 1, "")
+	return funcValue
+}
+
+// extractFuncScalar returns some scalar that can be used in comparisons. It is
+// a cheap operation.
+func (b *builder) extractFuncScalar(funcValue llvm.Value) llvm.Value {
+	return b.CreateExtractValue(funcValue, 1, "")
+}
+
+// extractFuncContext extracts the context pointer from this function value. It
+// is a cheap operation.
+func (b *builder) extractFuncContext(funcValue llvm.Value) llvm.Value {
+	return b.CreateExtractValue(funcValue, 0, "")
+}
+
+// decodeFuncValue extracts the context and the function pointer from this func
+// value. This may be an expensive operation.
+func (b *builder) decodeFuncValue(funcValue llvm.Value, sig *types.Signature) (funcPtr, context llvm.Value) {
+	context = b.CreateExtractValue(funcValue, 0, "")
+	switch b.FuncImplementation {
+	case "doubleword":
+		funcPtr = b.CreateExtractValue(funcValue, 1, "")
+	case "switch":
+		llvmSig := b.getRawFuncType(sig)
+		sigGlobal := b.getTypeCode(sig)
+		funcPtr = b.createRuntimeCall("getFuncPtr", []llvm.Value{funcValue, sigGlobal}, "")
+		funcPtr = b.CreateIntToPtr(funcPtr, llvmSig, "")
+	default:
+		panic("unimplemented func value variant")
+	}
+	return
+}
+
+// getFuncType returns the type of a func value given a signature.
+func (c *compilerContext) getFuncType(typ *types.Signature) llvm.Type {
+	switch c.FuncImplementation {
+	case "doubleword":
+		rawPtr := c.getRawFuncType(typ)
+		return c.ctx.StructType([]llvm.Type{c.i8ptrType, rawPtr}, false)
+	case "switch":
+		return c.getLLVMRuntimeType("funcValue")
+	default:
+		panic("unimplemented func value variant")
+	}
+}
+
+// getRawFuncType returns a LLVM function pointer type for a given signature.
+func (c *compilerContext) getRawFuncType(typ *types.Signature) llvm.Type {
+	// Get the return type.
+	var returnType llvm.Type
+	switch typ.Results().Len() {
+	case 0:
+		// No return values.
+		returnType = c.ctx.VoidType()
+	case 1:
+		// Just one return value.
+		returnType = c.getLLVMType(typ.Results().At(0).Type())
+	default:
+		// Multiple return values. Put them together in a struct.
+		// This appears to be the common way to handle multiple return values in
+		// LLVM.
+		members := make([]llvm.Type, typ.Results().Len())
+		for i := 0; i < typ.Results().Len(); i++ {
+			members[i] = c.getLLVMType(typ.Results().At(i).Type())
+		}
+		returnType = c.ctx.StructType(members, false)
+	}
+
+	// Get the parameter types.
+	var paramTypes []llvm.Type
+	if typ.Recv() != nil {
+		recv := c.getLLVMType(typ.Recv().Type())
+		if recv.StructName() == "runtime._interface" {
+			// This is a call on an interface, not a concrete type.
+			// The receiver is not an interface, but a i8* type.
+			recv = c.i8ptrType
+		}
+		for _, info := range expandFormalParamType(recv, "", nil) {
+			paramTypes = append(paramTypes, info.llvmType)
+		}
+	}
+	for i := 0; i < typ.Params().Len(); i++ {
+		subType := c.getLLVMType(typ.Params().At(i).Type())
+		for _, info := range expandFormalParamType(subType, "", nil) {
+			paramTypes = append(paramTypes, info.llvmType)
+		}
+	}
+	// All functions take these parameters at the end.
+	paramTypes = append(paramTypes, c.i8ptrType) // context
+	paramTypes = append(paramTypes, c.i8ptrType) // parent coroutine
+
+	// Make a func type out of the signature.
+	return llvm.PointerType(llvm.FunctionType(returnType, paramTypes, false), c.funcPtrAddrSpace)
+}
+
+// parseMakeClosure makes a function value (with context) from the given
+// closure expression.
+func (b *builder) parseMakeClosure(expr *ssa.MakeClosure) (llvm.Value, error) {
+	if len(expr.Bindings) == 0 {
+		panic("unexpected: MakeClosure without bound variables")
+	}
+	f := expr.Fn.(*ssa.Function)
+
+	// Collect all bound variables.
+	boundVars := make([]llvm.Value, len(expr.Bindings))
+	for i, binding := range expr.Bindings {
+		// The context stores the bound variables.
+		llvmBoundVar := b.getValue(binding)
+		boundVars[i] = llvmBoundVar
+	}
+
+	// Store the bound variables in a single object, allocating it on the heap
+	// if necessary.
+	context := b.emitPointerPack(boundVars)
+
+	// Create the closure.
+	return b.createFuncValue(b.getFunction(f), context, f.Signature), nil
+}

compiler/gc.go

@@ -0,0 +1,112 @@
+package compiler
+
+// This file provides IR transformations necessary for precise and portable
+// garbage collectors.
+
+import (
+	"go/token"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// trackExpr inserts pointer tracking intrinsics for the GC if the expression is
+// one of the expressions that need this.
+func (b *builder) trackExpr(expr ssa.Value, value llvm.Value) {
+	// There are uses of this expression, Make sure the pointers
+	// are tracked during GC.
+	switch expr := expr.(type) {
+	case *ssa.Alloc, *ssa.MakeChan, *ssa.MakeMap:
+		// These values are always of pointer type in IR.
+		b.trackPointer(value)
+	case *ssa.Call, *ssa.Convert, *ssa.MakeClosure, *ssa.MakeInterface, *ssa.MakeSlice, *ssa.Next:
+		if !value.IsNil() {
+			b.trackValue(value)
+		}
+	case *ssa.Select:
+		if alloca, ok := b.selectRecvBuf[expr]; ok {
+			if alloca.IsAUndefValue().IsNil() {
+				b.trackPointer(alloca)
+			}
+		}
+	case *ssa.UnOp:
+		switch expr.Op {
+		case token.MUL:
+			// Pointer dereference.
+			b.trackValue(value)
+		case token.ARROW:
+			// Channel receive operator.
+			// It's not necessary to look at commaOk here, because in that
+			// case it's just an aggregate and trackValue will extract the
+			// pointer in there (if there is one).
+			b.trackValue(value)
+		}
+	case *ssa.BinOp:
+		switch expr.Op {
+		case token.ADD:
+			// String concatenation.
+			b.trackValue(value)
+		}
+	}
+}
+
+// trackValue locates pointers in a value (possibly an aggregate) and tracks the
+// individual pointers
+func (b *builder) trackValue(value llvm.Value) {
+	typ := value.Type()
+	switch typ.TypeKind() {
+	case llvm.PointerTypeKind:
+		b.trackPointer(value)
+	case llvm.StructTypeKind:
+		if !typeHasPointers(typ) {
+			return
+		}
+		numElements := typ.StructElementTypesCount()
+		for i := 0; i < numElements; i++ {
+			subValue := b.CreateExtractValue(value, i, "")
+			b.trackValue(subValue)
+		}
+	case llvm.ArrayTypeKind:
+		if !typeHasPointers(typ) {
+			return
+		}
+		numElements := typ.ArrayLength()
+		for i := 0; i < numElements; i++ {
+			subValue := b.CreateExtractValue(value, i, "")
+			b.trackValue(subValue)
+		}
+	}
+}
+
+// trackPointer creates a call to runtime.trackPointer, bitcasting the poitner
+// first if needed. The input value must be of LLVM pointer type.
+func (b *builder) trackPointer(value llvm.Value) {
+	if value.Type() != b.i8ptrType {
+		value = b.CreateBitCast(value, b.i8ptrType, "")
+	}
+	b.createRuntimeCall("trackPointer", []llvm.Value{value}, "")
+}
+
+// typeHasPointers returns whether this type is a pointer or contains pointers.
+// If the type is an aggregate type, it will check whether there is a pointer
+// inside.
+func typeHasPointers(t llvm.Type) bool {
+	switch t.TypeKind() {
+	case llvm.PointerTypeKind:
+		return true
+	case llvm.StructTypeKind:
+		for _, subType := range t.StructElementTypes() {
+			if typeHasPointers(subType) {
+				return true
+			}
+		}
+		return false
+	case llvm.ArrayTypeKind:
+		if typeHasPointers(t.ElementType()) {
+			return true
+		}
+		return false
+	default:
+		return false
+	}
+}

compiler/goroutine.go

@@ -0,0 +1,194 @@
+package compiler
+
+// This file implements the 'go' keyword to start a new goroutine. See
+// goroutine-lowering.go for more details.
+
+import (
+	"go/token"
+
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createGoInstruction starts a new goroutine with the provided function pointer
+// and parameters.
+// In general, you should pass all regular parameters plus the context parameter.
+// There is one exception: the task-based scheduler needs to have the function
+// pointer passed in as a parameter too in addition to the context.
+//
+// Because a go statement doesn't return anything, return undef.
+func (b *builder) createGoInstruction(funcPtr llvm.Value, params []llvm.Value, prefix string, pos token.Pos) llvm.Value {
+	paramBundle := b.emitPointerPack(params)
+	var callee, stackSize llvm.Value
+	switch b.Scheduler {
+	case "none", "tasks":
+		callee = b.createGoroutineStartWrapper(funcPtr, prefix, pos)
+		if b.AutomaticStackSize {
+			// The stack size is not known until after linking. Call a dummy
+			// function that will be replaced with a load from a special ELF
+			// section that contains the stack size (and is modified after
+			// linking).
+			stackSizeFn := b.getFunction(b.program.ImportedPackage("internal/task").Members["getGoroutineStackSize"].(*ssa.Function))
+			stackSize = b.createCall(stackSizeFn, []llvm.Value{callee, llvm.Undef(b.i8ptrType), llvm.Undef(b.i8ptrType)}, "stacksize")
+		} else {
+			// The stack size is fixed at compile time. By emitting it here as a
+			// constant, it can be optimized.
+			stackSize = llvm.ConstInt(b.uintptrType, b.DefaultStackSize, false)
+		}
+	case "coroutines":
+		callee = b.CreatePtrToInt(funcPtr, b.uintptrType, "")
+		// There is no goroutine stack size: coroutines are used instead of
+		// stacks.
+		stackSize = llvm.Undef(b.uintptrType)
+	default:
+		panic("unreachable")
+	}
+	start := b.getFunction(b.program.ImportedPackage("internal/task").Members["start"].(*ssa.Function))
+	b.createCall(start, []llvm.Value{callee, paramBundle, stackSize, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
+	return llvm.Undef(funcPtr.Type().ElementType().ReturnType())
+}
+
+// createGoroutineStartWrapper creates a wrapper for the task-based
+// implementation of goroutines. For example, to call a function like this:
+//
+//     func add(x, y int) int { ... }
+//
+// It creates a wrapper like this:
+//
+//     func add$gowrapper(ptr *unsafe.Pointer) {
+//         args := (*struct{
+//             x, y int
+//         })(ptr)
+//         add(args.x, args.y)
+//     }
+//
+// This is useful because the task-based goroutine start implementation only
+// allows a single (pointer) argument to the newly started goroutine. Also, it
+// ignores the return value because newly started goroutines do not have a
+// return value.
+func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix string, pos token.Pos) llvm.Value {
+	var wrapper llvm.Value
+
+	builder := c.ctx.NewBuilder()
+	defer builder.Dispose()
+
+	if !fn.IsAFunction().IsNil() {
+		// See whether this wrapper has already been created. If so, return it.
+		name := fn.Name()
+		wrapper = c.mod.NamedFunction(name + "$gowrapper")
+		if !wrapper.IsNil() {
+			return llvm.ConstPtrToInt(wrapper, c.uintptrType)
+		}
+
+		// Create the wrapper.
+		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
+		wrapper = llvm.AddFunction(c.mod, name+"$gowrapper", wrapperType)
+		wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
+		wrapper.SetUnnamedAddr(true)
+		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", name))
+		entry := c.ctx.AddBasicBlock(wrapper, "entry")
+		builder.SetInsertPointAtEnd(entry)
+
+		if c.Debug {
+			pos := c.program.Fset.Position(pos)
+			diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
+				File:       c.getDIFile(pos.Filename),
+				Parameters: nil, // do not show parameters in debugger
+				Flags:      0,   // ?
+			})
+			difunc := c.dibuilder.CreateFunction(c.getDIFile(pos.Filename), llvm.DIFunction{
+				Name:         "<goroutine wrapper>",
+				File:         c.getDIFile(pos.Filename),
+				Line:         pos.Line,
+				Type:         diFuncType,
+				LocalToUnit:  true,
+				IsDefinition: true,
+				ScopeLine:    0,
+				Flags:        llvm.FlagPrototyped,
+				Optimized:    true,
+			})
+			wrapper.SetSubprogram(difunc)
+			builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
+		}
+
+		// Create the list of params for the call.
+		paramTypes := fn.Type().ElementType().ParamTypes()
+		params := llvmutil.EmitPointerUnpack(builder, c.mod, wrapper.Param(0), paramTypes[:len(paramTypes)-1])
+		params = append(params, llvm.Undef(c.i8ptrType))
+
+		// Create the call.
+		builder.CreateCall(fn, params, "")
+
+	} else {
+		// For a function pointer like this:
+		//
+		//     var funcPtr func(x, y int) int
+		//
+		// A wrapper like the following is created:
+		//
+		//     func .gowrapper(ptr *unsafe.Pointer) {
+		//         args := (*struct{
+		//             x, y int
+		//             fn   func(x, y int) int
+		//         })(ptr)
+		//         args.fn(x, y)
+		//     }
+		//
+		// With a bit of luck, identical wrapper functions like these can be
+		// merged into one.
+
+		// Create the wrapper.
+		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
+		wrapper = llvm.AddFunction(c.mod, prefix+".gowrapper", wrapperType)
+		wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
+		wrapper.SetUnnamedAddr(true)
+		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", ""))
+		entry := c.ctx.AddBasicBlock(wrapper, "entry")
+		builder.SetInsertPointAtEnd(entry)
+
+		if c.Debug {
+			pos := c.program.Fset.Position(pos)
+			diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
+				File:       c.getDIFile(pos.Filename),
+				Parameters: nil, // do not show parameters in debugger
+				Flags:      0,   // ?
+			})
+			difunc := c.dibuilder.CreateFunction(c.getDIFile(pos.Filename), llvm.DIFunction{
+				Name:         "<goroutine wrapper>",
+				File:         c.getDIFile(pos.Filename),
+				Line:         pos.Line,
+				Type:         diFuncType,
+				LocalToUnit:  true,
+				IsDefinition: true,
+				ScopeLine:    0,
+				Flags:        llvm.FlagPrototyped,
+				Optimized:    true,
+			})
+			wrapper.SetSubprogram(difunc)
+			builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
+		}
+
+		// Get the list of parameters, with the extra parameters at the end.
+		paramTypes := fn.Type().ElementType().ParamTypes()
+		paramTypes[len(paramTypes)-1] = fn.Type() // the last element is the function pointer
+		params := llvmutil.EmitPointerUnpack(builder, c.mod, wrapper.Param(0), paramTypes)
+
+		// Get the function pointer.
+		fnPtr := params[len(params)-1]
+
+		// Ignore the last param, which isn't used anymore.
+		// TODO: avoid this extra "parent handle" parameter in most functions.
+		params[len(params)-1] = llvm.Undef(c.i8ptrType)
+
+		// Create the call.
+		builder.CreateCall(fnPtr, params, "")
+	}
+
+	// Finish the function. Every basic block must end in a terminator, and
+	// because goroutines never return a value we can simply return void.
+	builder.CreateRetVoid()
+
+	// Return a ptrtoint of the wrapper, not the function itself.
+	return builder.CreatePtrToInt(wrapper, c.uintptrType, "")
+}

compiler/inlineasm.go

@@ -0,0 +1,247 @@
+package compiler
+
+// This file implements inline asm support by calling special functions.
+
+import (
+	"fmt"
+	"go/constant"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// This is a compiler builtin, which emits a piece of inline assembly with no
+// operands or return values. It is useful for trivial instructions, like wfi in
+// ARM or sleep in AVR.
+//
+//     func Asm(asm string)
+//
+// The provided assembly must be a constant.
+func (b *builder) createInlineAsm(args []ssa.Value) (llvm.Value, error) {
+	// Magic function: insert inline assembly instead of calling it.
+	fnType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{}, false)
+	asm := constant.StringVal(args[0].(*ssa.Const).Value)
+	target := llvm.InlineAsm(fnType, asm, "", true, false, 0)
+	return b.CreateCall(target, nil, ""), nil
+}
+
+// This is a compiler builtin, which allows assembly to be called in a flexible
+// way.
+//
+//     func AsmFull(asm string, regs map[string]interface{}) uintptr
+//
+// The asm parameter must be a constant string. The regs parameter must be
+// provided immediately. For example:
+//
+//     arm.AsmFull(
+//         "str {value}, {result}",
+//         map[string]interface{}{
+//             "value":  1
+//             "result": &dest,
+//         })
+func (b *builder) createInlineAsmFull(instr *ssa.CallCommon) (llvm.Value, error) {
+	asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
+	registers := map[string]llvm.Value{}
+	if registerMap, ok := instr.Args[1].(*ssa.MakeMap); ok {
+		for _, r := range *registerMap.Referrers() {
+			switch r := r.(type) {
+			case *ssa.DebugRef:
+				// ignore
+			case *ssa.MapUpdate:
+				if r.Block() != registerMap.Block() {
+					return llvm.Value{}, b.makeError(instr.Pos(), "register value map must be created in the same basic block")
+				}
+				key := constant.StringVal(r.Key.(*ssa.Const).Value)
+				registers[key] = b.getValue(r.Value.(*ssa.MakeInterface).X)
+			case *ssa.Call:
+				if r.Common() == instr {
+					break
+				}
+			default:
+				return llvm.Value{}, b.makeError(instr.Pos(), "don't know how to handle argument to inline assembly: "+r.String())
+			}
+		}
+	}
+	// TODO: handle dollar signs in asm string
+	registerNumbers := map[string]int{}
+	var err error
+	argTypes := []llvm.Type{}
+	args := []llvm.Value{}
+	constraints := []string{}
+	hasOutput := false
+	asmString = regexp.MustCompile("\\{\\}").ReplaceAllStringFunc(asmString, func(s string) string {
+		hasOutput = true
+		return "$0"
+	})
+	if hasOutput {
+		constraints = append(constraints, "=&r")
+		registerNumbers[""] = 0
+	}
+	asmString = regexp.MustCompile("\\{[a-zA-Z]+\\}").ReplaceAllStringFunc(asmString, func(s string) string {
+		// TODO: skip strings like {r4} etc. that look like ARM push/pop
+		// instructions.
+		name := s[1 : len(s)-1]
+		if _, ok := registers[name]; !ok {
+			if err == nil {
+				err = b.makeError(instr.Pos(), "unknown register name: "+name)
+			}
+			return s
+		}
+		if _, ok := registerNumbers[name]; !ok {
+			registerNumbers[name] = len(registerNumbers)
+			argTypes = append(argTypes, registers[name].Type())
+			args = append(args, registers[name])
+			switch registers[name].Type().TypeKind() {
+			case llvm.IntegerTypeKind:
+				constraints = append(constraints, "r")
+			case llvm.PointerTypeKind:
+				constraints = append(constraints, "*m")
+			default:
+				err = b.makeError(instr.Pos(), "unknown type in inline assembly for value: "+name)
+				return s
+			}
+		}
+		return fmt.Sprintf("${%v}", registerNumbers[name])
+	})
+	if err != nil {
+		return llvm.Value{}, err
+	}
+	var outputType llvm.Type
+	if hasOutput {
+		outputType = b.uintptrType
+	} else {
+		outputType = b.ctx.VoidType()
+	}
+	fnType := llvm.FunctionType(outputType, argTypes, false)
+	target := llvm.InlineAsm(fnType, asmString, strings.Join(constraints, ","), true, false, 0)
+	result := b.CreateCall(target, args, "")
+	if hasOutput {
+		return result, nil
+	} else {
+		// Make sure we return something valid.
+		return llvm.ConstInt(b.uintptrType, 0, false), nil
+	}
+}
+
+// This is a compiler builtin which emits an inline SVCall instruction. It can
+// be one of:
+//
+//     func SVCall0(num uintptr) uintptr
+//     func SVCall1(num uintptr, a1 interface{}) uintptr
+//     func SVCall2(num uintptr, a1, a2 interface{}) uintptr
+//     func SVCall3(num uintptr, a1, a2, a3 interface{}) uintptr
+//     func SVCall4(num uintptr, a1, a2, a3, a4 interface{}) uintptr
+//
+// The num parameter must be a constant. All other parameters may be any scalar
+// value supported by LLVM inline assembly.
+func (b *builder) emitSVCall(args []ssa.Value) (llvm.Value, error) {
+	num, _ := constant.Uint64Val(args[0].(*ssa.Const).Value)
+	llvmArgs := []llvm.Value{}
+	argTypes := []llvm.Type{}
+	asm := "svc #" + strconv.FormatUint(num, 10)
+	constraints := "={r0}"
+	for i, arg := range args[1:] {
+		arg = arg.(*ssa.MakeInterface).X
+		if i == 0 {
+			constraints += ",0"
+		} else {
+			constraints += ",{r" + strconv.Itoa(i) + "}"
+		}
+		llvmValue := b.getValue(arg)
+		llvmArgs = append(llvmArgs, llvmValue)
+		argTypes = append(argTypes, llvmValue.Type())
+	}
+	// Implement the ARM calling convention by marking r1-r3 as
+	// clobbered. r0 is used as an output register so doesn't have to be
+	// marked as clobbered.
+	constraints += ",~{r1},~{r2},~{r3}"
+	fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+	target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
+	return b.CreateCall(target, llvmArgs, ""), nil
+}
+
+// This is a compiler builtin which emits an inline SVCall instruction. It can
+// be one of:
+//
+//     func SVCall0(num uintptr) uintptr
+//     func SVCall1(num uintptr, a1 interface{}) uintptr
+//     func SVCall2(num uintptr, a1, a2 interface{}) uintptr
+//     func SVCall3(num uintptr, a1, a2, a3 interface{}) uintptr
+//     func SVCall4(num uintptr, a1, a2, a3, a4 interface{}) uintptr
+//
+// The num parameter must be a constant. All other parameters may be any scalar
+// value supported by LLVM inline assembly.
+// Same as emitSVCall but for AArch64
+func (b *builder) emitSV64Call(args []ssa.Value) (llvm.Value, error) {
+	num, _ := constant.Uint64Val(args[0].(*ssa.Const).Value)
+	llvmArgs := []llvm.Value{}
+	argTypes := []llvm.Type{}
+	asm := "svc #" + strconv.FormatUint(num, 10)
+	constraints := "={x0}"
+	for i, arg := range args[1:] {
+		arg = arg.(*ssa.MakeInterface).X
+		if i == 0 {
+			constraints += ",0"
+		} else {
+			constraints += ",{x" + strconv.Itoa(i) + "}"
+		}
+		llvmValue := b.getValue(arg)
+		llvmArgs = append(llvmArgs, llvmValue)
+		argTypes = append(argTypes, llvmValue.Type())
+	}
+	// Implement the ARM64 calling convention by marking x1-x7 as
+	// clobbered. x0 is used as an output register so doesn't have to be
+	// marked as clobbered.
+	constraints += ",~{x1},~{x2},~{x3},~{x4},~{x5},~{x6},~{x7}"
+	fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+	target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
+	return b.CreateCall(target, llvmArgs, ""), nil
+}
+
+// This is a compiler builtin which emits CSR instructions. It can be one of:
+//
+//     func (csr CSR) Get() uintptr
+//     func (csr CSR) Set(uintptr)
+//     func (csr CSR) SetBits(uintptr) uintptr
+//     func (csr CSR) ClearBits(uintptr) uintptr
+//
+// The csr parameter (method receiver) must be a constant. Other parameter can
+// be any value.
+func (b *builder) emitCSROperation(call *ssa.CallCommon) (llvm.Value, error) {
+	csrConst, ok := call.Args[0].(*ssa.Const)
+	if !ok {
+		return llvm.Value{}, b.makeError(call.Pos(), "CSR must be constant")
+	}
+	csr := csrConst.Uint64()
+	switch name := call.StaticCallee().Name(); name {
+	case "Get":
+		// Note that this instruction may have side effects, and thus must be
+		// marked as such.
+		fnType := llvm.FunctionType(b.uintptrType, nil, false)
+		asm := fmt.Sprintf("csrr $0, %d", csr)
+		target := llvm.InlineAsm(fnType, asm, "=r", true, false, 0)
+		return b.CreateCall(target, nil, ""), nil
+	case "Set":
+		fnType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{b.uintptrType}, false)
+		asm := fmt.Sprintf("csrw %d, $0", csr)
+		target := llvm.InlineAsm(fnType, asm, "r", true, false, 0)
+		return b.CreateCall(target, []llvm.Value{b.getValue(call.Args[1])}, ""), nil
+	case "SetBits":
+		// Note: it may be possible to optimize this to csrrsi in many cases.
+		fnType := llvm.FunctionType(b.uintptrType, []llvm.Type{b.uintptrType}, false)
+		asm := fmt.Sprintf("csrrs $0, %d, $1", csr)
+		target := llvm.InlineAsm(fnType, asm, "=r,r", true, false, 0)
+		return b.CreateCall(target, []llvm.Value{b.getValue(call.Args[1])}, ""), nil
+	case "ClearBits":
+		// Note: it may be possible to optimize this to csrrci in many cases.
+		fnType := llvm.FunctionType(b.uintptrType, []llvm.Type{b.uintptrType}, false)
+		asm := fmt.Sprintf("csrrc $0, %d, $1", csr)
+		target := llvm.InlineAsm(fnType, asm, "=r,r", true, false, 0)
+		return b.CreateCall(target, []llvm.Value{b.getValue(call.Args[1])}, ""), nil
+	default:
+		return llvm.Value{}, b.makeError(call.Pos(), "unknown CSR operation: "+name)
+	}
+}

compiler/interface.go

@@ -8,118 +8,257 @@ package compiler
 import (
 	"go/token"
 	"go/types"
+	"strconv"
+	"strings"
 
-	"github.com/aykevl/go-llvm"
-	"github.com/aykevl/tinygo/ir"
 	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
 )
 
-// parseMakeInterface emits the LLVM IR for the *ssa.MakeInterface instruction.
+// createMakeInterface emits the LLVM IR for the *ssa.MakeInterface instruction.
 // It tries to put the type in the interface value, but if that's not possible,
 // it will do an allocation of the right size and put that in the interface
 // value field.
 //
-// An interface value is a {typecode, value} tuple, or {i16, i8*} to be exact.
-func (c *Compiler) parseMakeInterface(val llvm.Value, typ types.Type, global string, pos token.Pos) (llvm.Value, error) {
-	var itfValue llvm.Value
-	size := c.targetData.TypeAllocSize(val.Type())
-	if size > c.targetData.TypeAllocSize(c.i8ptrType) {
-		if global != "" {
-			// Allocate in a global variable.
-			global := llvm.AddGlobal(c.mod, val.Type(), global+"$itfvalue")
-			global.SetInitializer(val)
-			global.SetLinkage(llvm.InternalLinkage)
-			global.SetGlobalConstant(true)
-			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
-			itfValueRaw := llvm.ConstInBoundsGEP(global, []llvm.Value{zero, zero})
-			itfValue = llvm.ConstBitCast(itfValueRaw, c.i8ptrType)
-		} else {
-			// Allocate on the heap and put a pointer in the interface.
-			// TODO: escape analysis.
-			sizeValue := llvm.ConstInt(c.uintptrType, size, false)
-			alloc := c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "makeinterface.alloc")
-			itfValueCast := c.builder.CreateBitCast(alloc, llvm.PointerType(val.Type(), 0), "makeinterface.cast.value")
-			c.builder.CreateStore(val, itfValueCast)
-			itfValue = c.builder.CreateBitCast(itfValueCast, c.i8ptrType, "makeinterface.cast.i8ptr")
-		}
-	} else if size == 0 {
-		itfValue = llvm.ConstPointerNull(c.i8ptrType)
-	} else {
-		// Directly place the value in the interface.
-		switch val.Type().TypeKind() {
-		case llvm.IntegerTypeKind:
-			itfValue = c.builder.CreateIntToPtr(val, c.i8ptrType, "makeinterface.cast.int")
-		case llvm.PointerTypeKind:
-			itfValue = c.builder.CreateBitCast(val, c.i8ptrType, "makeinterface.cast.ptr")
-		case llvm.StructTypeKind:
-			// A bitcast would be useful here, but bitcast doesn't allow
-			// aggregate types. So we'll bitcast it using an alloca.
-			// Hopefully this will get optimized away.
-			mem := c.builder.CreateAlloca(c.i8ptrType, "makeinterface.cast.struct")
-			memStructPtr := c.builder.CreateBitCast(mem, llvm.PointerType(val.Type(), 0), "makeinterface.cast.struct.cast")
-			c.builder.CreateStore(val, memStructPtr)
-			itfValue = c.builder.CreateLoad(mem, "makeinterface.cast.load")
-		default:
-			return llvm.Value{}, c.makeError(pos, "todo: makeinterface: cast small type to i8*")
-		}
-	}
-	itfTypeCodeGlobal := c.getTypeCode(typ)
-	itfMethodSetGlobal, err := c.getTypeMethodSet(typ)
-	if err != nil {
-		return llvm.Value{}, nil
-	}
-	itfTypeCode := c.createRuntimeCall("makeInterface", []llvm.Value{itfTypeCodeGlobal, itfMethodSetGlobal}, "makeinterface.typecode")
-	itf := llvm.Undef(c.mod.GetTypeByName("runtime._interface"))
-	itf = c.builder.CreateInsertValue(itf, itfTypeCode, 0, "")
-	itf = c.builder.CreateInsertValue(itf, itfValue, 1, "")
-	return itf, nil
+// An interface value is a {typecode, value} tuple named runtime._interface.
+func (b *builder) createMakeInterface(val llvm.Value, typ types.Type, pos token.Pos) llvm.Value {
+	itfValue := b.emitPointerPack([]llvm.Value{val})
+	itfTypeCodeGlobal := b.getTypeCode(typ)
+	itfTypeCode := b.CreatePtrToInt(itfTypeCodeGlobal, b.uintptrType, "")
+	itf := llvm.Undef(b.getLLVMRuntimeType("_interface"))
+	itf = b.CreateInsertValue(itf, itfTypeCode, 0, "")
+	itf = b.CreateInsertValue(itf, itfValue, 1, "")
+	return itf
 }
 
 // getTypeCode returns a reference to a type code.
 // It returns a pointer to an external global which should be replaced with the
 // real type in the interface lowering pass.
-func (c *Compiler) getTypeCode(typ types.Type) llvm.Value {
-	global := c.mod.NamedGlobal(typ.String() + "$type")
+func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
+	globalName := "reflect/types.type:" + getTypeCodeName(typ)
+	global := c.mod.NamedGlobal(globalName)
 	if global.IsNil() {
-		global = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), typ.String()+"$type")
+		// Create a new typecode global.
+		global = llvm.AddGlobal(c.mod, c.getLLVMRuntimeType("typecodeID"), globalName)
+		// Some type classes contain more information for underlying types or
+		// element types. Store it directly in the typecode global to make
+		// reflect lowering simpler.
+		var references llvm.Value
+		var length int64
+		var methodSet llvm.Value
+		switch typ := typ.(type) {
+		case *types.Named:
+			references = c.getTypeCode(typ.Underlying())
+		case *types.Chan:
+			references = c.getTypeCode(typ.Elem())
+		case *types.Pointer:
+			references = c.getTypeCode(typ.Elem())
+		case *types.Slice:
+			references = c.getTypeCode(typ.Elem())
+		case *types.Array:
+			references = c.getTypeCode(typ.Elem())
+			length = typ.Len()
+		case *types.Struct:
+			// Take a pointer to the typecodeID of the first field (if it exists).
+			structGlobal := c.makeStructTypeFields(typ)
+			references = llvm.ConstBitCast(structGlobal, global.Type())
+		case *types.Interface:
+			methodSetGlobal := c.getInterfaceMethodSet(typ)
+			references = llvm.ConstBitCast(methodSetGlobal, global.Type())
+		}
+		if _, ok := typ.Underlying().(*types.Interface); !ok {
+			methodSet = c.getTypeMethodSet(typ)
+		}
+		if !references.IsNil() || length != 0 || !methodSet.IsNil() {
+			// Set the 'references' field of the runtime.typecodeID struct.
+			globalValue := llvm.ConstNull(global.Type().ElementType())
+			if !references.IsNil() {
+				globalValue = llvm.ConstInsertValue(globalValue, references, []uint32{0})
+			}
+			if length != 0 {
+				lengthValue := llvm.ConstInt(c.uintptrType, uint64(length), false)
+				globalValue = llvm.ConstInsertValue(globalValue, lengthValue, []uint32{1})
+			}
+			if !methodSet.IsNil() {
+				globalValue = llvm.ConstInsertValue(globalValue, methodSet, []uint32{2})
+			}
+			global.SetInitializer(globalValue)
+			global.SetLinkage(llvm.LinkOnceODRLinkage)
+		}
 		global.SetGlobalConstant(true)
 	}
 	return global
 }
 
+// makeStructTypeFields creates a new global that stores all type information
+// related to this struct type, and returns the resulting global. This global is
+// actually an array of all the fields in the structs.
+func (c *compilerContext) makeStructTypeFields(typ *types.Struct) llvm.Value {
+	// The global is an array of runtime.structField structs.
+	runtimeStructField := c.getLLVMRuntimeType("structField")
+	structGlobalType := llvm.ArrayType(runtimeStructField, typ.NumFields())
+	structGlobal := llvm.AddGlobal(c.mod, structGlobalType, "reflect/types.structFields")
+	structGlobalValue := llvm.ConstNull(structGlobalType)
+	for i := 0; i < typ.NumFields(); i++ {
+		fieldGlobalValue := llvm.ConstNull(runtimeStructField)
+		fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, c.getTypeCode(typ.Field(i).Type()), []uint32{0})
+		fieldName := c.makeGlobalArray([]byte(typ.Field(i).Name()), "reflect/types.structFieldName", c.ctx.Int8Type())
+		fieldName.SetLinkage(llvm.PrivateLinkage)
+		fieldName.SetUnnamedAddr(true)
+		fieldName = llvm.ConstGEP(fieldName, []llvm.Value{
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+		})
+		fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldName, []uint32{1})
+		if typ.Tag(i) != "" {
+			fieldTag := c.makeGlobalArray([]byte(typ.Tag(i)), "reflect/types.structFieldTag", c.ctx.Int8Type())
+			fieldTag.SetLinkage(llvm.PrivateLinkage)
+			fieldTag.SetUnnamedAddr(true)
+			fieldTag = llvm.ConstGEP(fieldTag, []llvm.Value{
+				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			})
+			fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldTag, []uint32{2})
+		}
+		if typ.Field(i).Embedded() {
+			fieldEmbedded := llvm.ConstInt(c.ctx.Int1Type(), 1, false)
+			fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldEmbedded, []uint32{3})
+		}
+		structGlobalValue = llvm.ConstInsertValue(structGlobalValue, fieldGlobalValue, []uint32{uint32(i)})
+	}
+	structGlobal.SetInitializer(structGlobalValue)
+	structGlobal.SetUnnamedAddr(true)
+	structGlobal.SetLinkage(llvm.PrivateLinkage)
+	return structGlobal
+}
+
+// getTypeCodeName returns a name for this type that can be used in the
+// interface lowering pass to assign type codes as expected by the reflect
+// package. See getTypeCodeNum.
+func getTypeCodeName(t types.Type) string {
+	switch t := t.(type) {
+	case *types.Named:
+		return "named:" + t.String()
+	case *types.Array:
+		return "array:" + strconv.FormatInt(t.Len(), 10) + ":" + getTypeCodeName(t.Elem())
+	case *types.Basic:
+		var kind string
+		switch t.Kind() {
+		case types.Bool:
+			kind = "bool"
+		case types.Int:
+			kind = "int"
+		case types.Int8:
+			kind = "int8"
+		case types.Int16:
+			kind = "int16"
+		case types.Int32:
+			kind = "int32"
+		case types.Int64:
+			kind = "int64"
+		case types.Uint:
+			kind = "uint"
+		case types.Uint8:
+			kind = "uint8"
+		case types.Uint16:
+			kind = "uint16"
+		case types.Uint32:
+			kind = "uint32"
+		case types.Uint64:
+			kind = "uint64"
+		case types.Uintptr:
+			kind = "uintptr"
+		case types.Float32:
+			kind = "float32"
+		case types.Float64:
+			kind = "float64"
+		case types.Complex64:
+			kind = "complex64"
+		case types.Complex128:
+			kind = "complex128"
+		case types.String:
+			kind = "string"
+		case types.UnsafePointer:
+			kind = "unsafeptr"
+		default:
+			panic("unknown basic type: " + t.Name())
+		}
+		return "basic:" + kind
+	case *types.Chan:
+		return "chan:" + getTypeCodeName(t.Elem())
+	case *types.Interface:
+		methods := make([]string, t.NumMethods())
+		for i := 0; i < t.NumMethods(); i++ {
+			methods[i] = t.Method(i).Name() + ":" + getTypeCodeName(t.Method(i).Type())
+		}
+		return "interface:" + "{" + strings.Join(methods, ",") + "}"
+	case *types.Map:
+		keyType := getTypeCodeName(t.Key())
+		elemType := getTypeCodeName(t.Elem())
+		return "map:" + "{" + keyType + "," + elemType + "}"
+	case *types.Pointer:
+		return "pointer:" + getTypeCodeName(t.Elem())
+	case *types.Signature:
+		params := make([]string, t.Params().Len())
+		for i := 0; i < t.Params().Len(); i++ {
+			params[i] = getTypeCodeName(t.Params().At(i).Type())
+		}
+		results := make([]string, t.Results().Len())
+		for i := 0; i < t.Results().Len(); i++ {
+			results[i] = getTypeCodeName(t.Results().At(i).Type())
+		}
+		return "func:" + "{" + strings.Join(params, ",") + "}{" + strings.Join(results, ",") + "}"
+	case *types.Slice:
+		return "slice:" + getTypeCodeName(t.Elem())
+	case *types.Struct:
+		elems := make([]string, t.NumFields())
+		for i := 0; i < t.NumFields(); i++ {
+			embedded := ""
+			if t.Field(i).Embedded() {
+				embedded = "#"
+			}
+			elems[i] = embedded + t.Field(i).Name() + ":" + getTypeCodeName(t.Field(i).Type())
+			if t.Tag(i) != "" {
+				elems[i] += "`" + t.Tag(i) + "`"
+			}
+		}
+		return "struct:" + "{" + strings.Join(elems, ",") + "}"
+	default:
+		panic("unknown type: " + t.String())
+	}
+}
+
 // getTypeMethodSet returns a reference (GEP) to a global method set. This
 // method set should be unreferenced after the interface lowering pass.
-func (c *Compiler) getTypeMethodSet(typ types.Type) (llvm.Value, error) {
+func (c *compilerContext) getTypeMethodSet(typ types.Type) llvm.Value {
 	global := c.mod.NamedGlobal(typ.String() + "$methodset")
 	zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
 	if !global.IsNil() {
 		// the method set already exists
-		return llvm.ConstGEP(global, []llvm.Value{zero, zero}), nil
+		return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 	}
 
-	ms := c.ir.Program.MethodSets.MethodSet(typ)
+	ms := c.program.MethodSets.MethodSet(typ)
 	if ms.Len() == 0 {
 		// no methods, so can leave that one out
-		return llvm.ConstPointerNull(llvm.PointerType(c.mod.GetTypeByName("runtime.interfaceMethodInfo"), 0)), nil
+		return llvm.ConstPointerNull(llvm.PointerType(c.getLLVMRuntimeType("interfaceMethodInfo"), 0))
 	}
 
 	methods := make([]llvm.Value, ms.Len())
-	interfaceMethodInfoType := c.mod.GetTypeByName("runtime.interfaceMethodInfo")
+	interfaceMethodInfoType := c.getLLVMRuntimeType("interfaceMethodInfo")
 	for i := 0; i < ms.Len(); i++ {
 		method := ms.At(i)
 		signatureGlobal := c.getMethodSignature(method.Obj().(*types.Func))
-		f := c.ir.GetFunction(c.ir.Program.MethodValue(method))
-		if f.LLVMFn.IsNil() {
+		fn := c.program.MethodValue(method)
+		llvmFn := c.getFunction(fn)
+		if llvmFn.IsNil() {
 			// compiler error, so panic
-			panic("cannot find function: " + f.LinkName())
-		}
-		fn, err := c.getInterfaceInvokeWrapper(f)
-		if err != nil {
-			return llvm.Value{}, err
+			panic("cannot find function: " + c.getFunctionInfo(fn).linkName)
 		}
+		wrapper := c.getInterfaceInvokeWrapper(fn, llvmFn)
 		methodInfo := llvm.ConstNamedStruct(interfaceMethodInfoType, []llvm.Value{
 			signatureGlobal,
-			llvm.ConstBitCast(fn, c.i8ptrType),
+			llvm.ConstPtrToInt(wrapper, c.uintptrType),
 		})
 		methods[i] = methodInfo
 	}
@@ -128,41 +267,46 @@ func (c *Compiler) getTypeMethodSet(typ types.Type) (llvm.Value, error) {
 	global = llvm.AddGlobal(c.mod, arrayType, typ.String()+"$methodset")
 	global.SetInitializer(value)
 	global.SetGlobalConstant(true)
-	global.SetLinkage(llvm.PrivateLinkage)
-	return llvm.ConstGEP(global, []llvm.Value{zero, zero}), nil
+	global.SetLinkage(llvm.LinkOnceODRLinkage)
+	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }
 
 // getInterfaceMethodSet returns a global variable with the method set of the
 // given named interface type. This method set is used by the interface lowering
 // pass.
-func (c *Compiler) getInterfaceMethodSet(typ *types.Named) llvm.Value {
-	global := c.mod.NamedGlobal(typ.String() + "$interface")
+func (c *compilerContext) getInterfaceMethodSet(typ types.Type) llvm.Value {
+	name := typ.String()
+	if _, ok := typ.(*types.Named); !ok {
+		// Anonymous interface.
+		name = "reflect/types.interface:" + name
+	}
+	global := c.mod.NamedGlobal(name + "$interface")
 	zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
 	if !global.IsNil() {
 		// method set already exist, return it
 		return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 	}
 
-	// Every method is a *i16 reference indicating the signature of this method.
+	// Every method is a *i8 reference indicating the signature of this method.
 	methods := make([]llvm.Value, typ.Underlying().(*types.Interface).NumMethods())
 	for i := range methods {
 		method := typ.Underlying().(*types.Interface).Method(i)
 		methods[i] = c.getMethodSignature(method)
 	}
 
-	value := llvm.ConstArray(methods[0].Type(), methods)
-	global = llvm.AddGlobal(c.mod, value.Type(), typ.String()+"$interface")
+	value := llvm.ConstArray(c.i8ptrType, methods)
+	global = llvm.AddGlobal(c.mod, value.Type(), name+"$interface")
 	global.SetInitializer(value)
 	global.SetGlobalConstant(true)
-	global.SetLinkage(llvm.PrivateLinkage)
+	global.SetLinkage(llvm.LinkOnceODRLinkage)
 	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }
 
 // getMethodSignature returns a global variable which is a reference to an
-// external *i16 indicating the indicating the signature of this method. It is
+// external *i8 indicating the indicating the signature of this method. It is
 // used during the interface lowering pass.
-func (c *Compiler) getMethodSignature(method *types.Func) llvm.Value {
-	signature := ir.MethodSignature(method)
+func (c *compilerContext) getMethodSignature(method *types.Func) llvm.Value {
+	signature := methodSignature(method)
 	signatureGlobal := c.mod.NamedGlobal("func " + signature)
 	if signatureGlobal.IsNil() {
 		signatureGlobal = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), "func "+signature)
@@ -171,28 +315,18 @@ func (c *Compiler) getMethodSignature(method *types.Func) llvm.Value {
 	return signatureGlobal
 }
 
-// parseTypeAssert will emit the code for a typeassert, used in if statements
+// createTypeAssert will emit the code for a typeassert, used in if statements
 // and in type switches (Go SSA does not have type switches, only if/else
 // chains). Note that even though the Go SSA does not contain type switches,
 // LLVM will recognize the pattern and make it a real switch in many cases.
 //
 // Type asserts on concrete types are trivial: just compare type numbers. Type
 // asserts on interfaces are more difficult, see the comments in the function.
-func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) (llvm.Value, error) {
-	itf, err := c.parseExpr(frame, expr.X)
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	assertedType, err := c.getLLVMType(expr.AssertedType)
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	valueNil, err := c.getZeroValue(assertedType)
-	if err != nil {
-		return llvm.Value{}, err
-	}
+func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
+	itf := b.getValue(expr.X)
+	assertedType := b.getLLVMType(expr.AssertedType)
 
-	actualTypeNum := c.builder.CreateExtractValue(itf, 0, "interface.type")
+	actualTypeNum := b.CreateExtractValue(itf, 0, "interface.type")
 	commaOk := llvm.Value{}
 	if _, ok := expr.AssertedType.Underlying().(*types.Interface); ok {
 		// Type assert on interface type.
@@ -203,15 +337,21 @@ func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) (llvm.Val
 		// the main Go compiler, where the runtime checks whether the type
 		// implements each method of the interface. See:
 		// https://research.swtch.com/interfaces
-		methodSet := c.getInterfaceMethodSet(expr.AssertedType.(*types.Named))
-		commaOk = c.createRuntimeCall("interfaceImplements", []llvm.Value{actualTypeNum, methodSet}, "")
+		methodSet := b.getInterfaceMethodSet(expr.AssertedType)
+		commaOk = b.createRuntimeCall("interfaceImplements", []llvm.Value{actualTypeNum, methodSet}, "")
 
 	} else {
+		globalName := "reflect/types.type:" + getTypeCodeName(expr.AssertedType) + "$id"
+		assertedTypeCodeGlobal := b.mod.NamedGlobal(globalName)
+		if assertedTypeCodeGlobal.IsNil() {
+			// Create a new typecode global.
+			assertedTypeCodeGlobal = llvm.AddGlobal(b.mod, b.ctx.Int8Type(), globalName)
+			assertedTypeCodeGlobal.SetGlobalConstant(true)
+		}
 		// Type assert on concrete type.
 		// Call runtime.typeAssert, which will be lowered to a simple icmp or
 		// const false in the interface lowering pass.
-		assertedTypeCodeGlobal := c.getTypeCode(expr.AssertedType)
-		commaOk = c.createRuntimeCall("typeAssert", []llvm.Value{actualTypeNum, assertedTypeCodeGlobal}, "typecode")
+		commaOk = b.createRuntimeCall("typeAssert", []llvm.Value{actualTypeNum, assertedTypeCodeGlobal}, "typecode")
 	}
 
 	// Add 2 new basic blocks (that should get optimized away): one for the
@@ -225,15 +365,15 @@ func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) (llvm.Val
 	// typeassert should return a zero value, not an incorrectly casted
 	// value.
 
-	prevBlock := c.builder.GetInsertBlock()
-	okBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "typeassert.ok")
-	nextBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "typeassert.next")
-	frame.blockExits[frame.currentBlock] = nextBlock // adjust outgoing block for phi nodes
-	c.builder.CreateCondBr(commaOk, okBlock, nextBlock)
+	prevBlock := b.GetInsertBlock()
+	okBlock := b.ctx.AddBasicBlock(b.llvmFn, "typeassert.ok")
+	nextBlock := b.ctx.AddBasicBlock(b.llvmFn, "typeassert.next")
+	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+	b.CreateCondBr(commaOk, okBlock, nextBlock)
 
 	// Retrieve the value from the interface if the type assert was
 	// successful.
-	c.builder.SetInsertPointAtEnd(okBlock)
+	b.SetInsertPointAtEnd(okBlock)
 	var valueOk llvm.Value
 	if _, ok := expr.AssertedType.Underlying().(*types.Interface); ok {
 		// Type assert on interface type. Easy: just return the same
@@ -242,125 +382,83 @@ func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) (llvm.Val
 	} else {
 		// Type assert on concrete type. Extract the underlying type from
 		// the interface (but only after checking it matches).
-		valuePtr := c.builder.CreateExtractValue(itf, 1, "typeassert.value.ptr")
-		size := c.targetData.TypeAllocSize(assertedType)
-		if size > c.targetData.TypeAllocSize(c.i8ptrType) {
-			// Value was stored in an allocated buffer, load it from there.
-			valuePtrCast := c.builder.CreateBitCast(valuePtr, llvm.PointerType(assertedType, 0), "")
-			valueOk = c.builder.CreateLoad(valuePtrCast, "typeassert.value.ok")
-		} else if size == 0 {
-			valueOk, err = c.getZeroValue(assertedType)
-			if err != nil {
-				return llvm.Value{}, err
-			}
-		} else {
-			// Value was stored directly in the interface.
-			switch assertedType.TypeKind() {
-			case llvm.IntegerTypeKind:
-				valueOk = c.builder.CreatePtrToInt(valuePtr, assertedType, "typeassert.value.ok")
-			case llvm.PointerTypeKind:
-				valueOk = c.builder.CreateBitCast(valuePtr, assertedType, "typeassert.value.ok")
-			default: // struct, float, etc.
-				// A bitcast would be useful here, but bitcast doesn't allow
-				// aggregate types. So we'll bitcast it using an alloca.
-				// Hopefully this will get optimized away.
-				mem := c.builder.CreateAlloca(c.i8ptrType, "")
-				c.builder.CreateStore(valuePtr, mem)
-				memCast := c.builder.CreateBitCast(mem, llvm.PointerType(assertedType, 0), "")
-				valueOk = c.builder.CreateLoad(memCast, "typeassert.value.ok")
-			}
-		}
+		valuePtr := b.CreateExtractValue(itf, 1, "typeassert.value.ptr")
+		valueOk = b.emitPointerUnpack(valuePtr, []llvm.Type{assertedType})[0]
 	}
-	c.builder.CreateBr(nextBlock)
+	b.CreateBr(nextBlock)
 
 	// Continue after the if statement.
-	c.builder.SetInsertPointAtEnd(nextBlock)
-	phi := c.builder.CreatePHI(assertedType, "typeassert.value")
-	phi.AddIncoming([]llvm.Value{valueNil, valueOk}, []llvm.BasicBlock{prevBlock, okBlock})
+	b.SetInsertPointAtEnd(nextBlock)
+	phi := b.CreatePHI(assertedType, "typeassert.value")
+	phi.AddIncoming([]llvm.Value{llvm.ConstNull(assertedType), valueOk}, []llvm.BasicBlock{prevBlock, okBlock})
 
 	if expr.CommaOk {
-		tuple := c.ctx.ConstStruct([]llvm.Value{llvm.Undef(assertedType), llvm.Undef(c.ctx.Int1Type())}, false) // create empty tuple
-		tuple = c.builder.CreateInsertValue(tuple, phi, 0, "")                                                  // insert value
-		tuple = c.builder.CreateInsertValue(tuple, commaOk, 1, "")                                              // insert 'comma ok' boolean
-		return tuple, nil
+		tuple := b.ctx.ConstStruct([]llvm.Value{llvm.Undef(assertedType), llvm.Undef(b.ctx.Int1Type())}, false) // create empty tuple
+		tuple = b.CreateInsertValue(tuple, phi, 0, "")                                                          // insert value
+		tuple = b.CreateInsertValue(tuple, commaOk, 1, "")                                                      // insert 'comma ok' boolean
+		return tuple
 	} else {
 		// This is kind of dirty as the branch above becomes mostly useless,
 		// but hopefully this gets optimized away.
-		c.createRuntimeCall("interfaceTypeAssert", []llvm.Value{commaOk}, "")
-		return phi, nil
+		b.createRuntimeCall("interfaceTypeAssert", []llvm.Value{commaOk}, "")
+		return phi
 	}
 }
 
+// getInvokePtr creates an interface function pointer lookup for the specified invoke instruction, using a specified typecode.
+func (b *builder) getInvokePtr(instr *ssa.CallCommon, typecode llvm.Value) llvm.Value {
+	llvmFnType := b.getRawFuncType(instr.Method.Type().(*types.Signature))
+	values := []llvm.Value{
+		typecode,
+		b.getInterfaceMethodSet(instr.Value.Type()),
+		b.getMethodSignature(instr.Method),
+	}
+	fn := b.createRuntimeCall("interfaceMethod", values, "invoke.func")
+	return b.CreateIntToPtr(fn, llvmFnType, "invoke.func.cast")
+}
+
 // getInvokeCall creates and returns the function pointer and parameters of an
-// interface call. It can be used in a call or defer instruction.
-func (c *Compiler) getInvokeCall(frame *Frame, instr *ssa.CallCommon) (llvm.Value, []llvm.Value, error) {
+// interface call.
+func (b *builder) getInvokeCall(instr *ssa.CallCommon) (llvm.Value, []llvm.Value) {
 	// Call an interface method with dynamic dispatch.
-	itf, err := c.parseExpr(frame, instr.Value) // interface
-	if err != nil {
-		return llvm.Value{}, nil, err
-	}
+	itf := b.getValue(instr.Value) // interface
 
-	llvmFnType, err := c.getLLVMType(instr.Method.Type())
-	if err != nil {
-		return llvm.Value{}, nil, err
-	}
-	// getLLVMType() has created a closure type for us, but we don't actually
-	// want a closure type as an interface call can never be a closure call. So
-	// extract the function pointer type from the closure.
-	llvmFnType = llvmFnType.Subtypes()[1]
-
-	typecode := c.builder.CreateExtractValue(itf, 0, "invoke.typecode")
-	values := []llvm.Value{
-		typecode,
-		c.getInterfaceMethodSet(instr.Value.Type().(*types.Named)),
-		c.getMethodSignature(instr.Method),
-	}
-	fn := c.createRuntimeCall("interfaceMethod", values, "invoke.func")
-	fnCast := c.builder.CreateBitCast(fn, llvmFnType, "invoke.func.cast")
-	receiverValue := c.builder.CreateExtractValue(itf, 1, "invoke.func.receiver")
+	typecode := b.CreateExtractValue(itf, 0, "invoke.typecode")
+	fnCast := b.getInvokePtr(instr, typecode)
+	receiverValue := b.CreateExtractValue(itf, 1, "invoke.func.receiver")
 
 	args := []llvm.Value{receiverValue}
 	for _, arg := range instr.Args {
-		val, err := c.parseExpr(frame, arg)
-		if err != nil {
-			return llvm.Value{}, nil, err
-		}
-		args = append(args, val)
+		args = append(args, b.getValue(arg))
 	}
 	// Add the context parameter. An interface call never takes a context but we
 	// have to supply the parameter anyway.
-	args = append(args, llvm.Undef(c.i8ptrType))
+	args = append(args, llvm.Undef(b.i8ptrType))
+	// Add the parent goroutine handle.
+	args = append(args, llvm.Undef(b.i8ptrType))
 
-	return fnCast, args, nil
+	return fnCast, args
 }
 
-// interfaceInvokeWrapper keeps some state between getInterfaceInvokeWrapper and
-// createInterfaceInvokeWrapper. The former is called during IR construction
-// itself and the latter is called when finishing up the IR.
-type interfaceInvokeWrapper struct {
-	fn           *ir.Function
-	wrapper      llvm.Value
-	receiverType llvm.Type
-}
-
-// Wrap an interface method function pointer. The wrapper takes in a pointer to
-// the underlying value, dereferences it, and calls the real method. This
-// wrapper is only needed when the interface value actually doesn't fit in a
-// pointer and a pointer to the value must be created.
-func (c *Compiler) getInterfaceInvokeWrapper(f *ir.Function) (llvm.Value, error) {
-	wrapperName := f.LinkName() + "$invoke"
+// getInterfaceInvokeWrapper returns a wrapper for the given method so it can be
+// invoked from an interface. The wrapper takes in a pointer to the underlying
+// value, dereferences or unpacks it if necessary, and calls the real method.
+// If the method to wrap has a pointer receiver, no wrapping is necessary and
+// the function is returned directly.
+func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llvm.Value) llvm.Value {
+	wrapperName := llvmFn.Name() + "$invoke"
 	wrapper := c.mod.NamedFunction(wrapperName)
 	if !wrapper.IsNil() {
 		// Wrapper already created. Return it directly.
-		return wrapper, nil
+		return wrapper
 	}
 
 	// Get the expanded receiver type.
-	receiverType, err := c.getLLVMType(f.Params[0].Type())
-	if err != nil {
-		return llvm.Value{}, err
+	receiverType := c.getLLVMType(fn.Signature.Recv().Type())
+	var expandedReceiverType []llvm.Type
+	for _, info := range expandFormalParamType(receiverType, "", nil) {
+		expandedReceiverType = append(expandedReceiverType, info.llvmType)
 	}
-	expandedReceiverType := c.expandFormalParamType(receiverType)
 
 	// Does this method even need any wrapping?
 	if len(expandedReceiverType) == 1 && receiverType.TypeKind() == llvm.PointerTypeKind {
@@ -368,75 +466,93 @@ func (c *Compiler) getInterfaceInvokeWrapper(f *ir.Function) (llvm.Value, error)
 		// Casting a function signature to a different signature and calling it
 		// with a receiver pointer bitcasted to *i8 (as done in calls on an
 		// interface) is hopefully a safe (defined) operation.
-		return f.LLVMFn, nil
+		return llvmFn
 	}
 
 	// create wrapper function
-	fnType := f.LLVMFn.Type().ElementType()
+	fnType := llvmFn.Type().ElementType()
 	paramTypes := append([]llvm.Type{c.i8ptrType}, fnType.ParamTypes()[len(expandedReceiverType):]...)
 	wrapFnType := llvm.FunctionType(fnType.ReturnType(), paramTypes, false)
 	wrapper = llvm.AddFunction(c.mod, wrapperName, wrapFnType)
-	c.interfaceInvokeWrappers = append(c.interfaceInvokeWrappers, interfaceInvokeWrapper{
-		fn:           f,
-		wrapper:      wrapper,
-		receiverType: receiverType,
-	})
-	return wrapper, nil
-}
+	wrapper.LastParam().SetName("parentHandle")
 
-// createInterfaceInvokeWrapper finishes the work of getInterfaceInvokeWrapper,
-// see that function for details.
-func (c *Compiler) createInterfaceInvokeWrapper(state interfaceInvokeWrapper) error {
-	wrapper := state.wrapper
-	fn := state.fn
-	receiverType := state.receiverType
-	wrapper.SetLinkage(llvm.InternalLinkage)
+	wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
 	wrapper.SetUnnamedAddr(true)
 
+	// Create a new builder just to create this wrapper.
+	b := builder{
+		compilerContext: c,
+		Builder:         c.ctx.NewBuilder(),
+	}
+	defer b.Builder.Dispose()
+
 	// add debug info if needed
 	if c.Debug {
-		pos := c.ir.Program.Fset.Position(fn.Pos())
-		difunc, err := c.attachDebugInfoRaw(fn, wrapper, "$invoke", pos.Filename, pos.Line)
-		if err != nil {
-			return err
-		}
-		c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
+		pos := c.program.Fset.Position(fn.Pos())
+		difunc := c.attachDebugInfoRaw(fn, wrapper, "$invoke", pos.Filename, pos.Line)
+		b.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
 	}
 
 	// set up IR builder
-	block := c.ctx.AddBasicBlock(wrapper, "entry")
-	c.builder.SetInsertPointAtEnd(block)
+	block := b.ctx.AddBasicBlock(wrapper, "entry")
+	b.SetInsertPointAtEnd(block)
 
-	var receiverPtr llvm.Value
-	if c.targetData.TypeAllocSize(receiverType) > c.targetData.TypeAllocSize(c.i8ptrType) {
-		// The receiver is passed in using a pointer. We have to load it here
-		// and pass it by value to the real function.
-
-		// Load the underlying value.
-		receiverPtrType := llvm.PointerType(receiverType, 0)
-		receiverPtr = c.builder.CreateBitCast(wrapper.Param(0), receiverPtrType, "receiver.ptr")
+	receiverValue := b.emitPointerUnpack(wrapper.Param(0), []llvm.Type{receiverType})[0]
+	params := append(b.expandFormalParam(receiverValue), wrapper.Params()[1:]...)
+	if llvmFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
+		b.CreateCall(llvmFn, params, "")
+		b.CreateRetVoid()
 	} else {
-		// The value is stored in the interface, but it is of type struct which
-		// is expanded to multiple parameters (e.g. {i8, i8}). So we have to
-		// receive the struct as parameter, expand it, and pass it on to the
-		// real function.
-
-		// Cast the passed-in i8* to the struct value (using an alloca) and
-		// extract its values.
-		alloca := c.builder.CreateAlloca(c.i8ptrType, "receiver.alloca")
-		c.builder.CreateStore(wrapper.Param(0), alloca)
-		receiverPtr = c.builder.CreateBitCast(alloca, llvm.PointerType(receiverType, 0), "receiver.ptr")
+		ret := b.CreateCall(llvmFn, params, "ret")
+		b.CreateRet(ret)
 	}
 
-	receiverValue := c.builder.CreateLoad(receiverPtr, "receiver")
-	params := append(c.expandFormalParam(receiverValue), wrapper.Params()[1:]...)
-	if fn.LLVMFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
-		c.builder.CreateCall(fn.LLVMFn, params, "")
-		c.builder.CreateRetVoid()
-	} else {
-		ret := c.builder.CreateCall(fn.LLVMFn, params, "ret")
-		c.builder.CreateRet(ret)
-	}
-
-	return nil
+	return wrapper
+}
+
+// methodSignature creates a readable version of a method signature (including
+// the function name, excluding the receiver name). This string is used
+// internally to match interfaces and to call the correct method on an
+// interface. Examples:
+//
+//     String() string
+//     Read([]byte) (int, error)
+func methodSignature(method *types.Func) string {
+	return method.Name() + signature(method.Type().(*types.Signature))
+}
+
+// Make a readable version of a function (pointer) signature.
+// Examples:
+//
+//     () string
+//     (string, int) (int, error)
+func signature(sig *types.Signature) string {
+	s := ""
+	if sig.Params().Len() == 0 {
+		s += "()"
+	} else {
+		s += "("
+		for i := 0; i < sig.Params().Len(); i++ {
+			if i > 0 {
+				s += ", "
+			}
+			s += sig.Params().At(i).Type().String()
+		}
+		s += ")"
+	}
+	if sig.Results().Len() == 0 {
+		// keep as-is
+	} else if sig.Results().Len() == 1 {
+		s += " " + sig.Results().At(0).Type().String()
+	} else {
+		s += " ("
+		for i := 0; i < sig.Results().Len(); i++ {
+			if i > 0 {
+				s += ", "
+			}
+			s += sig.Results().At(i).Type().String()
+		}
+		s += ")"
+	}
+	return s
 }

compiler/interrupt.go

@@ -0,0 +1,92 @@
+package compiler
+
+import (
+	"strconv"
+	"strings"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createInterruptGlobal creates a new runtime/interrupt.Interrupt struct that
+// will be lowered to a real interrupt during interrupt lowering.
+//
+// This two-stage approach allows unused interrupts to be optimized away if
+// necessary.
+func (b *builder) createInterruptGlobal(instr *ssa.CallCommon) (llvm.Value, error) {
+	// Get the interrupt number, which must be a compile-time constant.
+	id, ok := instr.Args[0].(*ssa.Const)
+	if !ok {
+		return llvm.Value{}, b.makeError(instr.Pos(), "interrupt ID is not a constant")
+	}
+
+	// Get the func value, which also must be a compile time constant.
+	// Note that bound functions are allowed if the function has a pointer
+	// receiver and is a global. This is rather strict but still allows for
+	// idiomatic Go code.
+	funcValue := b.getValue(instr.Args[1])
+	if funcValue.IsAConstant().IsNil() {
+		// Try to determine the cause of the non-constantness for a nice error
+		// message.
+		switch instr.Args[1].(type) {
+		case *ssa.MakeClosure:
+			// This may also be a bound method.
+			return llvm.Value{}, b.makeError(instr.Pos(), "closures are not supported in interrupt.New")
+		}
+		// Fall back to a generic error.
+		return llvm.Value{}, b.makeError(instr.Pos(), "interrupt function must be constant")
+	}
+
+	// Create a new global of type runtime/interrupt.handle. Globals of this
+	// type are lowered in the interrupt lowering pass.
+	globalType := b.program.ImportedPackage("runtime/interrupt").Type("handle").Type()
+	globalLLVMType := b.getLLVMType(globalType)
+	globalName := "runtime/interrupt.$interrupt" + strconv.FormatInt(id.Int64(), 10)
+	if global := b.mod.NamedGlobal(globalName); !global.IsNil() {
+		return llvm.Value{}, b.makeError(instr.Pos(), "interrupt redeclared in this program")
+	}
+	global := llvm.AddGlobal(b.mod, globalLLVMType, globalName)
+	global.SetVisibility(llvm.HiddenVisibility)
+	global.SetGlobalConstant(true)
+	global.SetUnnamedAddr(true)
+	initializer := llvm.ConstNull(globalLLVMType)
+	initializer = llvm.ConstInsertValue(initializer, funcValue, []uint32{0})
+	initializer = llvm.ConstInsertValue(initializer, llvm.ConstInt(b.intType, uint64(id.Int64()), true), []uint32{1, 0})
+	global.SetInitializer(initializer)
+
+	// Add debug info to the interrupt global.
+	if b.Debug {
+		pos := b.program.Fset.Position(instr.Pos())
+		diglobal := b.dibuilder.CreateGlobalVariableExpression(b.getDIFile(pos.Filename), llvm.DIGlobalVariableExpression{
+			Name:        "interrupt" + strconv.FormatInt(id.Int64(), 10),
+			LinkageName: globalName,
+			File:        b.getDIFile(pos.Filename),
+			Line:        pos.Line,
+			Type:        b.getDIType(globalType),
+			Expr:        b.dibuilder.CreateExpression(nil),
+			LocalToUnit: false,
+		})
+		global.AddMetadata(0, diglobal)
+	}
+
+	// Create the runtime/interrupt.Interrupt type. It is a struct with a single
+	// member of type int.
+	num := llvm.ConstPtrToInt(global, b.intType)
+	interrupt := llvm.ConstNamedStruct(b.mod.GetTypeByName("runtime/interrupt.Interrupt"), []llvm.Value{num})
+
+	// Add dummy "use" call for AVR, because interrupts may be used even though
+	// they are never referenced again. This is unlike Cortex-M or the RISC-V
+	// PLIC where each interrupt must be enabled using the interrupt number, and
+	// thus keeps the Interrupt object alive.
+	// This call is removed during interrupt lowering.
+	if strings.HasPrefix(b.Triple, "avr") {
+		useFn := b.mod.NamedFunction("runtime/interrupt.use")
+		if useFn.IsNil() {
+			useFnType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{interrupt.Type()}, false)
+			useFn = llvm.AddFunction(b.mod, "runtime/interrupt.use", useFnType)
+		}
+		b.CreateCall(useFn, []llvm.Value{interrupt}, "")
+	}
+
+	return interrupt, nil
+}

compiler/intrinsics.go

@@ -0,0 +1,50 @@
+package compiler
+
+// This file contains helper functions to create calls to LLVM intrinsics.
+
+import (
+	"strconv"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createMemoryCopyCall creates a call to a builtin LLVM memcpy or memmove
+// function, declaring this function if needed. These calls are treated
+// specially by optimization passes possibly resulting in better generated code,
+// and will otherwise be lowered to regular libc memcpy/memmove calls.
+func (b *builder) createMemoryCopyCall(fn *ssa.Function, args []ssa.Value) (llvm.Value, error) {
+	fnName := "llvm." + fn.Name() + ".p0i8.p0i8.i" + strconv.Itoa(b.uintptrType.IntTypeWidth())
+	llvmFn := b.mod.NamedFunction(fnName)
+	if llvmFn.IsNil() {
+		fnType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{b.i8ptrType, b.i8ptrType, b.uintptrType, b.ctx.Int1Type()}, false)
+		llvmFn = llvm.AddFunction(b.mod, fnName, fnType)
+	}
+	var params []llvm.Value
+	for _, param := range args {
+		params = append(params, b.getValue(param))
+	}
+	params = append(params, llvm.ConstInt(b.ctx.Int1Type(), 0, false))
+	b.CreateCall(llvmFn, params, "")
+	return llvm.Value{}, nil
+}
+
+// createMemoryZeroCall creates calls to llvm.memset.* to zero a block of
+// memory, declaring the function if needed. These calls will be lowered to
+// regular libc memset calls if they aren't optimized out in a different way.
+func (b *builder) createMemoryZeroCall(args []ssa.Value) (llvm.Value, error) {
+	fnName := "llvm.memset.p0i8.i" + strconv.Itoa(b.uintptrType.IntTypeWidth())
+	llvmFn := b.mod.NamedFunction(fnName)
+	if llvmFn.IsNil() {
+		fnType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{b.i8ptrType, b.ctx.Int8Type(), b.uintptrType, b.ctx.Int1Type()}, false)
+		llvmFn = llvm.AddFunction(b.mod, fnName, fnType)
+	}
+	params := []llvm.Value{
+		b.getValue(args[0]),
+		llvm.ConstInt(b.ctx.Int8Type(), 0, false),
+		b.getValue(args[1]),
+		llvm.ConstInt(b.ctx.Int1Type(), 0, false),
+	}
+	b.CreateCall(llvmFn, params, "")
+	return llvm.Value{}, nil
+}

compiler/ircheck/check.go

@@ -0,0 +1,194 @@
+// Package ircheck implements a checker for LLVM IR, that goes a bit further
+// than the regular LLVM IR verifier. Note that it checks different things, so
+// this is not a replacement for the LLVM verifier but does catch things that
+// the LLVM verifier doesn't catch.
+package ircheck
+
+import (
+	"errors"
+	"fmt"
+
+	"tinygo.org/x/go-llvm"
+)
+
+type checker struct {
+	ctx llvm.Context
+}
+
+func (c *checker) checkType(t llvm.Type, checked map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) error {
+	// prevent infinite recursion for self-referential types
+	if _, ok := checked[t]; ok {
+		return nil
+	}
+	checked[t] = struct{}{}
+
+	// check for any context mismatches
+	switch {
+	case t.Context() == c.ctx:
+		// this is correct
+	case t.Context() == llvm.GlobalContext():
+		// somewhere we accidentally used the global context instead of a real context
+		return fmt.Errorf("type %q uses global context", t.String())
+	default:
+		// we used some other context by accident
+		return fmt.Errorf("type %q uses context %v instead of the main context %v", t.Context(), c.ctx)
+	}
+
+	// if this is a composite type, check the components of the type
+	switch t.TypeKind() {
+	case llvm.VoidTypeKind, llvm.LabelTypeKind, llvm.TokenTypeKind, llvm.MetadataTypeKind:
+		// there should only be one of any of these
+		if s, ok := specials[t.TypeKind()]; !ok {
+			specials[t.TypeKind()] = t
+		} else if s != t {
+			return fmt.Errorf("duplicate special type %q: %v and %v", t.TypeKind().String(), t, s)
+		}
+	case llvm.FloatTypeKind, llvm.DoubleTypeKind, llvm.X86_FP80TypeKind, llvm.FP128TypeKind, llvm.PPC_FP128TypeKind:
+		// floating point numbers are primitives - nothing to recurse
+	case llvm.IntegerTypeKind:
+		// integers are primitives - nothing to recurse
+	case llvm.FunctionTypeKind:
+		// check arguments and return(s)
+		for i, v := range t.ParamTypes() {
+			if err := c.checkType(v, checked, specials); err != nil {
+				return fmt.Errorf("failed to verify argument %d of type %s: %s", i, t.String(), err.Error())
+			}
+		}
+		if err := c.checkType(t.ReturnType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify return type of type %s: %s", t.String(), err.Error())
+		}
+	case llvm.StructTypeKind:
+		// check all elements
+		for i, v := range t.StructElementTypes() {
+			if err := c.checkType(v, checked, specials); err != nil {
+				return fmt.Errorf("failed to verify type of field %d of struct type %s: %s", i, t.String(), err.Error())
+			}
+		}
+	case llvm.ArrayTypeKind:
+		// check element type
+		if err := c.checkType(t.ElementType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify element type of array type %s: %s", t.String(), err.Error())
+		}
+	case llvm.PointerTypeKind:
+		// check underlying type
+		if err := c.checkType(t.ElementType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify underlying type of pointer type %s: %s", t.String(), err.Error())
+		}
+	case llvm.VectorTypeKind:
+		// check element type
+		if err := c.checkType(t.ElementType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify element type of vector type %s: %s", t.String(), err.Error())
+		}
+	default:
+		return fmt.Errorf("unrecognized kind %q of type %s", t.TypeKind(), t.String())
+	}
+
+	return nil
+}
+
+func (c *checker) checkValue(v llvm.Value, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) error {
+	// check type
+	if err := c.checkType(v.Type(), types, specials); err != nil {
+		return fmt.Errorf("failed to verify type of value: %s", err.Error())
+	}
+
+	// check if this is an undefined void
+	if v.IsUndef() && v.Type().TypeKind() == llvm.VoidTypeKind {
+		return errors.New("encountered undefined void value")
+	}
+
+	return nil
+}
+
+func (c *checker) checkInstruction(inst llvm.Value, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) error {
+	// check value properties
+	if err := c.checkValue(inst, types, specials); err != nil {
+		return errorAt(inst, err.Error())
+	}
+
+	// The alloca instruction can be present in every basic block. However,
+	// allocas in basic blocks other than the entry basic block have a number of
+	// problems:
+	//   * They are hard to optimize, leading to potential missed optimizations.
+	//   * They may cause stack overflows in loops that would otherwise be
+	//     innocent.
+	//   * They cause extra code to be generated, because it requires the use of
+	//     a frame pointer.
+	//   * Perhaps most importantly, the coroutine lowering pass of LLVM (as of
+	//     LLVM 9) cannot deal with these allocas:
+	//     https://llvm.org/docs/Coroutines.html
+	// Therefore, alloca instructions should be limited to the entry block.
+	if !inst.IsAAllocaInst().IsNil() {
+		if inst.InstructionParent() != inst.InstructionParent().Parent().EntryBasicBlock() {
+			return errorAt(inst, "internal error: non-static alloca")
+		}
+	}
+
+	// check operands
+	for i := 0; i < inst.OperandsCount(); i++ {
+		if err := c.checkValue(inst.Operand(i), types, specials); err != nil {
+			return errorAt(inst, fmt.Sprintf("failed to validate operand %d of instruction %q: %s", i, inst.Name(), err.Error()))
+		}
+	}
+
+	return nil
+}
+
+func (c *checker) checkBasicBlock(bb llvm.BasicBlock, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) []error {
+	// check basic block value and type
+	var errs []error
+	if err := c.checkValue(bb.AsValue(), types, specials); err != nil {
+		errs = append(errs, errorAt(bb.Parent(), fmt.Sprintf("failed to validate value of basic block %s: %v", bb.AsValue().Name(), err)))
+	}
+
+	// check instructions
+	for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+		if err := c.checkInstruction(inst, types, specials); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	return errs
+}
+
+func (c *checker) checkFunction(fn llvm.Value, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) []error {
+	// check function value and type
+	var errs []error
+	if err := c.checkValue(fn, types, specials); err != nil {
+		errs = append(errs, fmt.Errorf("failed to validate value of function %s: %s", fn.Name(), err.Error()))
+	}
+
+	// check basic blocks
+	for bb := fn.FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+		errs = append(errs, c.checkBasicBlock(bb, types, specials)...)
+	}
+
+	return errs
+}
+
+// Module checks the given module and returns a slice of error, if there are
+// any.
+func Module(mod llvm.Module) []error {
+	// check for any context mismatches
+	var errs []error
+	c := checker{
+		ctx: mod.Context(),
+	}
+	if c.ctx == llvm.GlobalContext() {
+		// somewhere we accidentally used the global context instead of a real context
+		errs = append(errs, errors.New("module uses global context"))
+	}
+
+	types := map[llvm.Type]struct{}{}
+	specials := map[llvm.TypeKind]llvm.Type{}
+	for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+		errs = append(errs, c.checkFunction(fn, types, specials)...)
+	}
+	for g := mod.FirstGlobal(); !g.IsNil(); g = llvm.NextGlobal(g) {
+		if err := c.checkValue(g, types, specials); err != nil {
+			errs = append(errs, fmt.Errorf("failed to verify global %s of module: %s", g.Name(), err.Error()))
+		}
+	}
+
+	return errs
+}

compiler/ircheck/errors.go

@@ -0,0 +1,48 @@
+package ircheck
+
+import (
+	"go/scanner"
+	"go/token"
+	"path/filepath"
+
+	"tinygo.org/x/go-llvm"
+)
+
+// errorAt returns an error value at the location of the instruction.
+// The location information may not be complete as it depends on debug
+// information in the IR.
+func errorAt(inst llvm.Value, msg string) scanner.Error {
+	return scanner.Error{
+		Pos: getPosition(inst),
+		Msg: msg,
+	}
+}
+
+// getPosition returns the position information for the given value, as far as
+// it is available.
+func getPosition(val llvm.Value) token.Position {
+	if !val.IsAInstruction().IsNil() {
+		loc := val.InstructionDebugLoc()
+		if loc.IsNil() {
+			return token.Position{}
+		}
+		file := loc.LocationScope().ScopeFile()
+		return token.Position{
+			Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+			Line:     int(loc.LocationLine()),
+			Column:   int(loc.LocationColumn()),
+		}
+	} else if !val.IsAFunction().IsNil() {
+		loc := val.Subprogram()
+		if loc.IsNil() {
+			return token.Position{}
+		}
+		file := loc.ScopeFile()
+		return token.Position{
+			Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+			Line:     int(loc.SubprogramLine()),
+		}
+	} else {
+		return token.Position{}
+	}
+}

compiler/llvm.go

@@ -0,0 +1,69 @@
+package compiler
+
+import (
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
+	"tinygo.org/x/go-llvm"
+)
+
+// This file contains helper functions for LLVM that are not exposed in the Go
+// bindings.
+
+// Return a list of values (actually, instructions) where this value is used as
+// an operand.
+func getUses(value llvm.Value) []llvm.Value {
+	if value.IsNil() {
+		return nil
+	}
+	var uses []llvm.Value
+	use := value.FirstUse()
+	for !use.IsNil() {
+		uses = append(uses, use.User())
+		use = use.NextUse()
+	}
+	return uses
+}
+
+// createTemporaryAlloca creates a new alloca in the entry block and adds
+// lifetime start information in the IR signalling that the alloca won't be used
+// before this point.
+//
+// This is useful for creating temporary allocas for intrinsics. Don't forget to
+// end the lifetime using emitLifetimeEnd after you're done with it.
+func (b *builder) createTemporaryAlloca(t llvm.Type, name string) (alloca, bitcast, size llvm.Value) {
+	return llvmutil.CreateTemporaryAlloca(b.Builder, b.mod, t, name)
+}
+
+// emitLifetimeEnd signals the end of an (alloca) lifetime by calling the
+// llvm.lifetime.end intrinsic. It is commonly used together with
+// createTemporaryAlloca.
+func (b *builder) emitLifetimeEnd(ptr, size llvm.Value) {
+	llvmutil.EmitLifetimeEnd(b.Builder, b.mod, ptr, size)
+}
+
+// emitPointerPack packs the list of values into a single pointer value using
+// bitcasts, or else allocates a value on the heap if it cannot be packed in the
+// pointer value directly. It returns the pointer with the packed data.
+func (b *builder) emitPointerPack(values []llvm.Value) llvm.Value {
+	return llvmutil.EmitPointerPack(b.Builder, b.mod, b.NeedsStackObjects, values)
+}
+
+// emitPointerUnpack extracts a list of values packed using emitPointerPack.
+func (b *builder) emitPointerUnpack(ptr llvm.Value, valueTypes []llvm.Type) []llvm.Value {
+	return llvmutil.EmitPointerUnpack(b.Builder, b.mod, ptr, valueTypes)
+}
+
+// makeGlobalArray creates a new LLVM global with the given name and integers as
+// contents, and returns the global.
+// Note that it is left with the default linkage etc., you should set
+// linkage/constant/etc properties yourself.
+func (c *compilerContext) makeGlobalArray(buf []byte, name string, elementType llvm.Type) llvm.Value {
+	globalType := llvm.ArrayType(elementType, len(buf))
+	global := llvm.AddGlobal(c.mod, globalType, name)
+	value := llvm.Undef(globalType)
+	for i := 0; i < len(buf); i++ {
+		ch := uint64(buf[i])
+		value = llvm.ConstInsertValue(value, llvm.ConstInt(elementType, ch, false), []uint32{uint32(i)})
+	}
+	global.SetInitializer(value)
+	return global
+}

compiler/llvmutil/llvm.go

@@ -0,0 +1,168 @@
+// Package llvmutil contains utility functions used across multiple compiler
+// packages. For example, they may be used by both the compiler pacakge and
+// transformation packages.
+//
+// Normally, utility packages are avoided. However, in this case, the utility
+// functions are non-trivial and hard to get right. Copying them to multiple
+// places would be a big risk if only one of them is updated.
+package llvmutil
+
+import "tinygo.org/x/go-llvm"
+
+// CreateEntryBlockAlloca creates a new alloca in the entry block, even though
+// the IR builder is located elsewhere. It assumes that the insert point is
+// at the end of the current block.
+func CreateEntryBlockAlloca(builder llvm.Builder, t llvm.Type, name string) llvm.Value {
+	currentBlock := builder.GetInsertBlock()
+	entryBlock := currentBlock.Parent().EntryBasicBlock()
+	if entryBlock.FirstInstruction().IsNil() {
+		builder.SetInsertPointAtEnd(entryBlock)
+	} else {
+		builder.SetInsertPointBefore(entryBlock.FirstInstruction())
+	}
+	alloca := builder.CreateAlloca(t, name)
+	builder.SetInsertPointAtEnd(currentBlock)
+	return alloca
+}
+
+// CreateTemporaryAlloca creates a new alloca in the entry block and adds
+// lifetime start infromation in the IR signalling that the alloca won't be used
+// before this point.
+//
+// This is useful for creating temporary allocas for intrinsics. Don't forget to
+// end the lifetime using emitLifetimeEnd after you're done with it.
+func CreateTemporaryAlloca(builder llvm.Builder, mod llvm.Module, t llvm.Type, name string) (alloca, bitcast, size llvm.Value) {
+	ctx := t.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	alloca = CreateEntryBlockAlloca(builder, t, name)
+	bitcast = builder.CreateBitCast(alloca, i8ptrType, name+".bitcast")
+	size = llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(t), false)
+	builder.CreateCall(getLifetimeStartFunc(mod), []llvm.Value{size, bitcast}, "")
+	return
+}
+
+// CreateInstructionAlloca creates an alloca in the entry block, and places lifetime control intrinsics around the instruction
+func CreateInstructionAlloca(builder llvm.Builder, mod llvm.Module, t llvm.Type, inst llvm.Value, name string) llvm.Value {
+	ctx := mod.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+
+	alloca := CreateEntryBlockAlloca(builder, t, name)
+	builder.SetInsertPointBefore(inst)
+	bitcast := builder.CreateBitCast(alloca, i8ptrType, name+".bitcast")
+	size := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(t), false)
+	builder.CreateCall(getLifetimeStartFunc(mod), []llvm.Value{size, bitcast}, "")
+	if next := llvm.NextInstruction(inst); !next.IsNil() {
+		builder.SetInsertPointBefore(next)
+	} else {
+		builder.SetInsertPointAtEnd(inst.InstructionParent())
+	}
+	builder.CreateCall(getLifetimeEndFunc(mod), []llvm.Value{size, bitcast}, "")
+	return alloca
+}
+
+// EmitLifetimeEnd signals the end of an (alloca) lifetime by calling the
+// llvm.lifetime.end intrinsic. It is commonly used together with
+// createTemporaryAlloca.
+func EmitLifetimeEnd(builder llvm.Builder, mod llvm.Module, ptr, size llvm.Value) {
+	builder.CreateCall(getLifetimeEndFunc(mod), []llvm.Value{size, ptr}, "")
+}
+
+// getLifetimeStartFunc returns the llvm.lifetime.start intrinsic and creates it
+// first if it doesn't exist yet.
+func getLifetimeStartFunc(mod llvm.Module) llvm.Value {
+	fn := mod.NamedFunction("llvm.lifetime.start.p0i8")
+	ctx := mod.Context()
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	if fn.IsNil() {
+		fnType := llvm.FunctionType(ctx.VoidType(), []llvm.Type{ctx.Int64Type(), i8ptrType}, false)
+		fn = llvm.AddFunction(mod, "llvm.lifetime.start.p0i8", fnType)
+	}
+	return fn
+}
+
+// getLifetimeEndFunc returns the llvm.lifetime.end intrinsic and creates it
+// first if it doesn't exist yet.
+func getLifetimeEndFunc(mod llvm.Module) llvm.Value {
+	fn := mod.NamedFunction("llvm.lifetime.end.p0i8")
+	ctx := mod.Context()
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	if fn.IsNil() {
+		fnType := llvm.FunctionType(ctx.VoidType(), []llvm.Type{ctx.Int64Type(), i8ptrType}, false)
+		fn = llvm.AddFunction(mod, "llvm.lifetime.end.p0i8", fnType)
+	}
+	return fn
+}
+
+// SplitBasicBlock splits a LLVM basic block into two parts. All instructions
+// after afterInst are moved into a new basic block (created right after the
+// current one) with the given name.
+func SplitBasicBlock(builder llvm.Builder, afterInst llvm.Value, insertAfter llvm.BasicBlock, name string) llvm.BasicBlock {
+	oldBlock := afterInst.InstructionParent()
+	newBlock := afterInst.Type().Context().InsertBasicBlock(insertAfter, name)
+	var nextInstructions []llvm.Value // values to move
+
+	// Collect to-be-moved instructions.
+	inst := afterInst
+	for {
+		inst = llvm.NextInstruction(inst)
+		if inst.IsNil() {
+			break
+		}
+		nextInstructions = append(nextInstructions, inst)
+	}
+
+	// Move instructions.
+	builder.SetInsertPointAtEnd(newBlock)
+	for _, inst := range nextInstructions {
+		inst.RemoveFromParentAsInstruction()
+		builder.Insert(inst)
+	}
+
+	// Find PHI nodes to update.
+	var phiNodes []llvm.Value // PHI nodes to update
+	for bb := insertAfter.Parent().FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+		for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+			if inst.IsAPHINode().IsNil() {
+				continue
+			}
+			needsUpdate := false
+			incomingCount := inst.IncomingCount()
+			for i := 0; i < incomingCount; i++ {
+				if inst.IncomingBlock(i) == oldBlock {
+					needsUpdate = true
+					break
+				}
+			}
+			if !needsUpdate {
+				// PHI node has no incoming edge from the old block.
+				continue
+			}
+			phiNodes = append(phiNodes, inst)
+		}
+	}
+
+	// Update PHI nodes.
+	for _, phi := range phiNodes {
+		builder.SetInsertPointBefore(phi)
+		newPhi := builder.CreatePHI(phi.Type(), "")
+		incomingCount := phi.IncomingCount()
+		incomingVals := make([]llvm.Value, incomingCount)
+		incomingBlocks := make([]llvm.BasicBlock, incomingCount)
+		for i := 0; i < incomingCount; i++ {
+			value := phi.IncomingValue(i)
+			block := phi.IncomingBlock(i)
+			if block == oldBlock {
+				block = newBlock
+			}
+			incomingVals[i] = value
+			incomingBlocks[i] = block
+		}
+		newPhi.AddIncoming(incomingVals, incomingBlocks)
+		phi.ReplaceAllUsesWith(newPhi)
+		phi.EraseFromParentAsInstruction()
+	}
+
+	return newBlock
+}

compiler/llvmutil/wordpack.go

@@ -0,0 +1,182 @@
+package llvmutil
+
+// This file contains utility functions to pack and unpack sets of values. It
+// can take in a list of values and tries to store it efficiently in the pointer
+// itself if possible and legal.
+
+import (
+	"tinygo.org/x/go-llvm"
+)
+
+// EmitPointerPack packs the list of values into a single pointer value using
+// bitcasts, or else allocates a value on the heap if it cannot be packed in the
+// pointer value directly. It returns the pointer with the packed data.
+// If the values are all constants, they are be stored in a constant global and deduplicated.
+func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bool, values []llvm.Value) llvm.Value {
+	ctx := mod.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
+	uintptrType := ctx.IntType(llvm.NewTargetData(mod.DataLayout()).PointerSize() * 8)
+
+	valueTypes := make([]llvm.Type, len(values))
+	for i, value := range values {
+		valueTypes[i] = value.Type()
+	}
+	packedType := ctx.StructType(valueTypes, false)
+
+	// Allocate memory for the packed data.
+	size := targetData.TypeAllocSize(packedType)
+	if size == 0 {
+		return llvm.ConstPointerNull(i8ptrType)
+	} else if len(values) == 1 && values[0].Type().TypeKind() == llvm.PointerTypeKind {
+		return builder.CreateBitCast(values[0], i8ptrType, "pack.ptr")
+	} else if size <= targetData.TypeAllocSize(i8ptrType) {
+		// Packed data fits in a pointer, so store it directly inside the
+		// pointer.
+		if len(values) == 1 && values[0].Type().TypeKind() == llvm.IntegerTypeKind {
+			// Try to keep this cast in SSA form.
+			return builder.CreateIntToPtr(values[0], i8ptrType, "pack.int")
+		}
+
+		// Because packedType is a struct and we have to cast it to a *i8, store
+		// it in a *i8 alloca first and load the *i8 value from there. This is
+		// effectively a bitcast.
+		packedAlloc, _, _ := CreateTemporaryAlloca(builder, mod, i8ptrType, "")
+
+		if size < targetData.TypeAllocSize(i8ptrType) {
+			// The alloca is bigger than the value that will be stored in it.
+			// To avoid having some bits undefined, zero the alloca first.
+			// Hopefully this will get optimized away.
+			builder.CreateStore(llvm.ConstNull(i8ptrType), packedAlloc)
+		}
+
+		// Store all values in the alloca.
+		packedAllocCast := builder.CreateBitCast(packedAlloc, llvm.PointerType(packedType, 0), "")
+		for i, value := range values {
+			indices := []llvm.Value{
+				llvm.ConstInt(ctx.Int32Type(), 0, false),
+				llvm.ConstInt(ctx.Int32Type(), uint64(i), false),
+			}
+			gep := builder.CreateInBoundsGEP(packedAllocCast, indices, "")
+			builder.CreateStore(value, gep)
+		}
+
+		// Load value (the *i8) from the alloca.
+		result := builder.CreateLoad(packedAlloc, "")
+
+		// End the lifetime of the alloca, to help the optimizer.
+		packedPtr := builder.CreateBitCast(packedAlloc, i8ptrType, "")
+		packedSize := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(packedAlloc.Type()), false)
+		EmitLifetimeEnd(builder, mod, packedPtr, packedSize)
+
+		return result
+	} else {
+		// Check if the values are all constants.
+		constant := true
+		for _, v := range values {
+			if !v.IsConstant() {
+				constant = false
+				break
+			}
+		}
+
+		if constant {
+			// The data is known at compile time, so store it in a constant global.
+			// The global address is marked as unnamed, which allows LLVM to merge duplicates.
+			funcName := builder.GetInsertBlock().Parent().Name()
+			global := llvm.AddGlobal(mod, packedType, funcName+"$pack")
+			global.SetInitializer(ctx.ConstStruct(values, false))
+			global.SetGlobalConstant(true)
+			global.SetUnnamedAddr(true)
+			global.SetLinkage(llvm.PrivateLinkage)
+			return llvm.ConstBitCast(global, i8ptrType)
+		}
+
+		// Packed data is bigger than a pointer, so allocate it on the heap.
+		sizeValue := llvm.ConstInt(uintptrType, size, false)
+		alloc := mod.NamedFunction("runtime.alloc")
+		packedHeapAlloc := builder.CreateCall(alloc, []llvm.Value{
+			sizeValue,
+			llvm.Undef(i8ptrType),            // unused context parameter
+			llvm.ConstPointerNull(i8ptrType), // coroutine handle
+		}, "")
+		if needsStackObjects {
+			trackPointer := mod.NamedFunction("runtime.trackPointer")
+			builder.CreateCall(trackPointer, []llvm.Value{
+				packedHeapAlloc,
+				llvm.Undef(i8ptrType),            // unused context parameter
+				llvm.ConstPointerNull(i8ptrType), // coroutine handle
+			}, "")
+		}
+		packedAlloc := builder.CreateBitCast(packedHeapAlloc, llvm.PointerType(packedType, 0), "")
+
+		// Store all values in the heap pointer.
+		for i, value := range values {
+			indices := []llvm.Value{
+				llvm.ConstInt(ctx.Int32Type(), 0, false),
+				llvm.ConstInt(ctx.Int32Type(), uint64(i), false),
+			}
+			gep := builder.CreateInBoundsGEP(packedAlloc, indices, "")
+			builder.CreateStore(value, gep)
+		}
+
+		// Return the original heap allocation pointer, which already is an *i8.
+		return packedHeapAlloc
+	}
+}
+
+// EmitPointerUnpack extracts a list of values packed using EmitPointerPack.
+func EmitPointerUnpack(builder llvm.Builder, mod llvm.Module, ptr llvm.Value, valueTypes []llvm.Type) []llvm.Value {
+	ctx := mod.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
+	uintptrType := ctx.IntType(llvm.NewTargetData(mod.DataLayout()).PointerSize() * 8)
+
+	packedType := ctx.StructType(valueTypes, false)
+
+	// Get a correctly-typed pointer to the packed data.
+	var packedAlloc, packedRawAlloc llvm.Value
+	size := targetData.TypeAllocSize(packedType)
+	if size == 0 {
+		// No data to unpack.
+	} else if len(valueTypes) == 1 && valueTypes[0].TypeKind() == llvm.PointerTypeKind {
+		// A single pointer is always stored directly.
+		return []llvm.Value{builder.CreateBitCast(ptr, valueTypes[0], "unpack.ptr")}
+	} else if size <= targetData.TypeAllocSize(i8ptrType) {
+		// Packed data stored directly in pointer.
+		if len(valueTypes) == 1 && valueTypes[0].TypeKind() == llvm.IntegerTypeKind {
+			// Keep this cast in SSA form.
+			return []llvm.Value{builder.CreatePtrToInt(ptr, valueTypes[0], "unpack.int")}
+		}
+		// Fallback: load it using an alloca.
+		packedRawAlloc, _, _ = CreateTemporaryAlloca(builder, mod, llvm.PointerType(i8ptrType, 0), "unpack.raw.alloc")
+		packedRawValue := builder.CreateBitCast(ptr, llvm.PointerType(i8ptrType, 0), "unpack.raw.value")
+		builder.CreateStore(packedRawValue, packedRawAlloc)
+		packedAlloc = builder.CreateBitCast(packedRawAlloc, llvm.PointerType(packedType, 0), "unpack.alloc")
+	} else {
+		// Packed data stored on the heap. Bitcast the passed-in pointer to the
+		// correct pointer type.
+		packedAlloc = builder.CreateBitCast(ptr, llvm.PointerType(packedType, 0), "unpack.raw.ptr")
+	}
+	// Load each value from the packed data.
+	values := make([]llvm.Value, len(valueTypes))
+	for i, valueType := range valueTypes {
+		if targetData.TypeAllocSize(valueType) == 0 {
+			// This value has length zero, so there's nothing to load.
+			values[i] = llvm.ConstNull(valueType)
+			continue
+		}
+		indices := []llvm.Value{
+			llvm.ConstInt(ctx.Int32Type(), 0, false),
+			llvm.ConstInt(ctx.Int32Type(), uint64(i), false),
+		}
+		gep := builder.CreateInBoundsGEP(packedAlloc, indices, "")
+		values[i] = builder.CreateLoad(gep, "")
+	}
+	if !packedRawAlloc.IsNil() {
+		allocPtr := builder.CreateBitCast(packedRawAlloc, i8ptrType, "")
+		allocSize := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(uintptrType), false)
+		EmitLifetimeEnd(builder, mod, allocPtr, allocSize)
+	}
+	return values
+}

compiler/map.go

@@ -6,112 +6,175 @@ import (
 	"go/token"
 	"go/types"
 
-	"github.com/aykevl/go-llvm"
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
 )
 
-func (c *Compiler) emitMapLookup(keyType, valueType types.Type, m, key llvm.Value, commaOk bool, pos token.Pos) (llvm.Value, error) {
-	llvmValueType, err := c.getLLVMType(valueType)
-	if err != nil {
-		return llvm.Value{}, err
+// createMakeMap creates a new map object (runtime.hashmap) by allocating and
+// initializing an appropriately sized object.
+func (b *builder) createMakeMap(expr *ssa.MakeMap) (llvm.Value, error) {
+	mapType := expr.Type().Underlying().(*types.Map)
+	keyType := mapType.Key().Underlying()
+	llvmValueType := b.getLLVMType(mapType.Elem().Underlying())
+	var llvmKeyType llvm.Type
+	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
+		// String keys.
+		llvmKeyType = b.getLLVMType(keyType)
+	} else if hashmapIsBinaryKey(keyType) {
+		// Trivially comparable keys.
+		llvmKeyType = b.getLLVMType(keyType)
+	} else {
+		// All other keys. Implemented as map[interface{}]valueType for ease of
+		// implementation.
+		llvmKeyType = b.getLLVMRuntimeType("_interface")
 	}
-	mapValueAlloca := c.builder.CreateAlloca(llvmValueType, "hashmap.value")
-	mapValuePtr := c.builder.CreateBitCast(mapValueAlloca, c.i8ptrType, "hashmap.valueptr")
+	keySize := b.targetData.TypeAllocSize(llvmKeyType)
+	valueSize := b.targetData.TypeAllocSize(llvmValueType)
+	llvmKeySize := llvm.ConstInt(b.ctx.Int8Type(), keySize, false)
+	llvmValueSize := llvm.ConstInt(b.ctx.Int8Type(), valueSize, false)
+	sizeHint := llvm.ConstInt(b.uintptrType, 8, false)
+	if expr.Reserve != nil {
+		sizeHint = b.getValue(expr.Reserve)
+		var err error
+		sizeHint, err = b.createConvert(expr.Reserve.Type(), types.Typ[types.Uintptr], sizeHint, expr.Pos())
+		if err != nil {
+			return llvm.Value{}, err
+		}
+	}
+	hashmap := b.createRuntimeCall("hashmapMake", []llvm.Value{llvmKeySize, llvmValueSize, sizeHint}, "")
+	return hashmap, nil
+}
+
+// createMapLookup returns the value in a map. It calls a runtime function
+// depending on the map key type to load the map value and its comma-ok value.
+func (b *builder) createMapLookup(keyType, valueType types.Type, m, key llvm.Value, commaOk bool, pos token.Pos) (llvm.Value, error) {
+	llvmValueType := b.getLLVMType(valueType)
+
+	// Allocate the memory for the resulting type. Do not zero this memory: it
+	// will be zeroed by the hashmap get implementation if the key is not
+	// present in the map.
+	mapValueAlloca, mapValuePtr, mapValueAllocaSize := b.createTemporaryAlloca(llvmValueType, "hashmap.value")
+
+	// We need the map size (with type uintptr) to pass to the hashmap*Get
+	// functions. This is necessary because those *Get functions are valid on
+	// nil maps, and they'll need to zero the value pointer by that number of
+	// bytes.
+	mapValueSize := mapValueAllocaSize
+	if mapValueSize.Type().IntTypeWidth() > b.uintptrType.IntTypeWidth() {
+		mapValueSize = llvm.ConstTrunc(mapValueSize, b.uintptrType)
+	}
+
+	// Do the lookup. How it is done depends on the key type.
 	var commaOkValue llvm.Value
+	keyType = keyType.Underlying()
 	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
 		// key is a string
-		params := []llvm.Value{m, key, mapValuePtr}
-		commaOkValue = c.createRuntimeCall("hashmapStringGet", params, "")
+		params := []llvm.Value{m, key, mapValuePtr, mapValueSize}
+		commaOkValue = b.createRuntimeCall("hashmapStringGet", params, "")
 	} else if hashmapIsBinaryKey(keyType) {
 		// key can be compared with runtime.memequal
-		keyAlloca := c.builder.CreateAlloca(key.Type(), "hashmap.key")
-		c.builder.CreateStore(key, keyAlloca)
-		keyPtr := c.builder.CreateBitCast(keyAlloca, c.i8ptrType, "hashmap.keyptr")
-		params := []llvm.Value{m, keyPtr, mapValuePtr}
-		commaOkValue = c.createRuntimeCall("hashmapBinaryGet", params, "")
+		// Store the key in an alloca, in the entry block to avoid dynamic stack
+		// growth.
+		mapKeyAlloca, mapKeyPtr, mapKeySize := b.createTemporaryAlloca(key.Type(), "hashmap.key")
+		b.CreateStore(key, mapKeyAlloca)
+		// Fetch the value from the hashmap.
+		params := []llvm.Value{m, mapKeyPtr, mapValuePtr, mapValueSize}
+		commaOkValue = b.createRuntimeCall("hashmapBinaryGet", params, "")
+		b.emitLifetimeEnd(mapKeyPtr, mapKeySize)
 	} else {
-		return llvm.Value{}, c.makeError(pos, "todo: map lookup key type: "+keyType.String())
+		// Not trivially comparable using memcmp. Make it an interface instead.
+		itfKey := key
+		if _, ok := keyType.(*types.Interface); !ok {
+			// Not already an interface, so convert it to an interface now.
+			itfKey = b.createMakeInterface(key, keyType, pos)
+		}
+		params := []llvm.Value{m, itfKey, mapValuePtr, mapValueSize}
+		commaOkValue = b.createRuntimeCall("hashmapInterfaceGet", params, "")
 	}
-	mapValue := c.builder.CreateLoad(mapValueAlloca, "")
+
+	// Load the resulting value from the hashmap. The value is set to the zero
+	// value if the key doesn't exist in the hashmap.
+	mapValue := b.CreateLoad(mapValueAlloca, "")
+	b.emitLifetimeEnd(mapValuePtr, mapValueAllocaSize)
+
 	if commaOk {
-		tuple := llvm.Undef(c.ctx.StructType([]llvm.Type{llvmValueType, c.ctx.Int1Type()}, false))
-		tuple = c.builder.CreateInsertValue(tuple, mapValue, 0, "")
-		tuple = c.builder.CreateInsertValue(tuple, commaOkValue, 1, "")
+		tuple := llvm.Undef(b.ctx.StructType([]llvm.Type{llvmValueType, b.ctx.Int1Type()}, false))
+		tuple = b.CreateInsertValue(tuple, mapValue, 0, "")
+		tuple = b.CreateInsertValue(tuple, commaOkValue, 1, "")
 		return tuple, nil
 	} else {
 		return mapValue, nil
 	}
 }
 
-func (c *Compiler) emitMapUpdate(keyType types.Type, m, key, value llvm.Value, pos token.Pos) error {
-	valueAlloca := c.builder.CreateAlloca(value.Type(), "hashmap.value")
-	c.builder.CreateStore(value, valueAlloca)
-	valuePtr := c.builder.CreateBitCast(valueAlloca, c.i8ptrType, "hashmap.valueptr")
+// createMapUpdate updates a map key to a given value, by creating an
+// appropriate runtime call.
+func (b *builder) createMapUpdate(keyType types.Type, m, key, value llvm.Value, pos token.Pos) {
+	valueAlloca, valuePtr, valueSize := b.createTemporaryAlloca(value.Type(), "hashmap.value")
+	b.CreateStore(value, valueAlloca)
 	keyType = keyType.Underlying()
 	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
 		// key is a string
 		params := []llvm.Value{m, key, valuePtr}
-		c.createRuntimeCall("hashmapStringSet", params, "")
-		return nil
+		b.createRuntimeCall("hashmapStringSet", params, "")
 	} else if hashmapIsBinaryKey(keyType) {
 		// key can be compared with runtime.memequal
-		keyAlloca := c.builder.CreateAlloca(key.Type(), "hashmap.key")
-		c.builder.CreateStore(key, keyAlloca)
-		keyPtr := c.builder.CreateBitCast(keyAlloca, c.i8ptrType, "hashmap.keyptr")
+		keyAlloca, keyPtr, keySize := b.createTemporaryAlloca(key.Type(), "hashmap.key")
+		b.CreateStore(key, keyAlloca)
 		params := []llvm.Value{m, keyPtr, valuePtr}
-		c.createRuntimeCall("hashmapBinarySet", params, "")
-		return nil
+		b.createRuntimeCall("hashmapBinarySet", params, "")
+		b.emitLifetimeEnd(keyPtr, keySize)
 	} else {
-		return c.makeError(pos, "todo: map update key type: "+keyType.String())
+		// Key is not trivially comparable, so compare it as an interface instead.
+		itfKey := key
+		if _, ok := keyType.(*types.Interface); !ok {
+			// Not already an interface, so convert it to an interface first.
+			itfKey = b.createMakeInterface(key, keyType, pos)
+		}
+		params := []llvm.Value{m, itfKey, valuePtr}
+		b.createRuntimeCall("hashmapInterfaceSet", params, "")
 	}
+	b.emitLifetimeEnd(valuePtr, valueSize)
 }
 
-func (c *Compiler) emitMapDelete(keyType types.Type, m, key llvm.Value, pos token.Pos) error {
+// createMapDelete deletes a key from a map by calling the appropriate runtime
+// function. It is the implementation of the Go delete() builtin.
+func (b *builder) createMapDelete(keyType types.Type, m, key llvm.Value, pos token.Pos) error {
 	keyType = keyType.Underlying()
 	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
 		// key is a string
 		params := []llvm.Value{m, key}
-		c.createRuntimeCall("hashmapStringDelete", params, "")
+		b.createRuntimeCall("hashmapStringDelete", params, "")
 		return nil
 	} else if hashmapIsBinaryKey(keyType) {
-		keyAlloca := c.builder.CreateAlloca(key.Type(), "hashmap.key")
-		c.builder.CreateStore(key, keyAlloca)
-		keyPtr := c.builder.CreateBitCast(keyAlloca, c.i8ptrType, "hashmap.keyptr")
+		keyAlloca, keyPtr, keySize := b.createTemporaryAlloca(key.Type(), "hashmap.key")
+		b.CreateStore(key, keyAlloca)
 		params := []llvm.Value{m, keyPtr}
-		c.createRuntimeCall("hashmapBinaryDelete", params, "")
+		b.createRuntimeCall("hashmapBinaryDelete", params, "")
+		b.emitLifetimeEnd(keyPtr, keySize)
 		return nil
 	} else {
-		return c.makeError(pos, "todo: map delete key type: "+keyType.String())
+		// Key is not trivially comparable, so compare it as an interface
+		// instead.
+		itfKey := key
+		if _, ok := keyType.(*types.Interface); !ok {
+			// Not already an interface, so convert it to an interface first.
+			itfKey = b.createMakeInterface(key, keyType, pos)
+		}
+		params := []llvm.Value{m, itfKey}
+		b.createRuntimeCall("hashmapInterfaceDelete", params, "")
+		return nil
 	}
 }
 
-// Get FNV-1a hash of this string.
-//
-// https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash
-func hashmapHash(data []byte) uint32 {
-	var result uint32 = 2166136261 // FNV offset basis
-	for _, c := range data {
-		result ^= uint32(c)
-		result *= 16777619 // FNV prime
-	}
-	return result
-}
-
-// Get the topmost 8 bits of the hash, without using a special value (like 0).
-func hashmapTopHash(hash uint32) uint8 {
-	tophash := uint8(hash >> 24)
-	if tophash < 1 {
-		// 0 means empty slot, so make it bigger.
-		tophash += 1
-	}
-	return tophash
-}
-
 // Returns true if this key type does not contain strings, interfaces etc., so
 // can be compared with runtime.memequal.
 func hashmapIsBinaryKey(keyType types.Type) bool {
 	switch keyType := keyType.(type) {
 	case *types.Basic:
 		return keyType.Info()&(types.IsBoolean|types.IsInteger) != 0
+	case *types.Pointer:
+		return true
 	case *types.Struct:
 		for i := 0; i < keyType.NumFields(); i++ {
 			fieldType := keyType.Field(i).Type().Underlying()
@@ -120,6 +183,10 @@ func hashmapIsBinaryKey(keyType types.Type) bool {
 			}
 		}
 		return true
+	case *types.Array:
+		return hashmapIsBinaryKey(keyType.Elem())
+	case *types.Named:
+		return hashmapIsBinaryKey(keyType.Underlying())
 	default:
 		return false
 	}

compiler/optimizer.go

@@ -1,341 +0,0 @@
-package compiler
-
-import (
-	"errors"
-
-	"github.com/aykevl/go-llvm"
-)
-
-// Run the LLVM optimizer over the module.
-// The inliner can be disabled (if necessary) by passing 0 to the inlinerThreshold.
-func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) error {
-	builder := llvm.NewPassManagerBuilder()
-	defer builder.Dispose()
-	builder.SetOptLevel(optLevel)
-	builder.SetSizeLevel(sizeLevel)
-	if inlinerThreshold != 0 {
-		builder.UseInlinerWithThreshold(inlinerThreshold)
-	}
-	builder.AddCoroutinePassesToExtensionPoints()
-
-	// Run function passes for each function.
-	funcPasses := llvm.NewFunctionPassManagerForModule(c.mod)
-	defer funcPasses.Dispose()
-	builder.PopulateFunc(funcPasses)
-	funcPasses.InitializeFunc()
-	for fn := c.mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
-		funcPasses.RunFunc(fn)
-	}
-	funcPasses.FinalizeFunc()
-
-	if optLevel > 0 {
-		// Run some preparatory passes for the Go optimizer.
-		goPasses := llvm.NewPassManager()
-		defer goPasses.Dispose()
-		goPasses.AddGlobalOptimizerPass()
-		goPasses.AddConstantPropagationPass()
-		goPasses.AddAggressiveDCEPass()
-		goPasses.AddFunctionAttrsPass()
-		goPasses.Run(c.mod)
-
-		// Run Go-specific optimization passes.
-		c.OptimizeMaps()
-		c.OptimizeStringToBytes()
-		c.OptimizeAllocs()
-		c.LowerInterfaces()
-
-		// After interfaces are lowered, there are many more opportunities for
-		// interprocedural optimizations. To get them to work, function
-		// attributes have to be updated first.
-		goPasses.Run(c.mod)
-
-		// Run TinyGo-specific interprocedural optimizations.
-		c.OptimizeAllocs()
-		c.OptimizeStringToBytes()
-	} else {
-		// Must be run at any optimization level.
-		c.LowerInterfaces()
-	}
-	if err := c.Verify(); err != nil {
-		return errors.New("optimizations caused a verification failure")
-	}
-
-	if sizeLevel >= 2 {
-		// Set the "optsize" attribute to make slightly smaller binaries at the
-		// cost of some performance.
-		kind := llvm.AttributeKindID("optsize")
-		attr := c.ctx.CreateEnumAttribute(kind, 0)
-		for fn := c.mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
-			fn.AddFunctionAttr(attr)
-		}
-	}
-
-	// Run module passes.
-	modPasses := llvm.NewPassManager()
-	defer modPasses.Dispose()
-	builder.Populate(modPasses)
-	modPasses.Run(c.mod)
-
-	return nil
-}
-
-// Eliminate created but not used maps.
-//
-// In the future, this should statically allocate created but never modified
-// maps. This has not yet been implemented, however.
-func (c *Compiler) OptimizeMaps() {
-	hashmapMake := c.mod.NamedFunction("runtime.hashmapMake")
-	if hashmapMake.IsNil() {
-		// nothing to optimize
-		return
-	}
-
-	hashmapBinarySet := c.mod.NamedFunction("runtime.hashmapBinarySet")
-	hashmapStringSet := c.mod.NamedFunction("runtime.hashmapStringSet")
-
-	for _, makeInst := range getUses(hashmapMake) {
-		updateInsts := []llvm.Value{}
-		unknownUses := false // are there any uses other than setting a value?
-
-		for _, use := range getUses(makeInst) {
-			if use := use.IsACallInst(); !use.IsNil() {
-				switch use.CalledValue() {
-				case hashmapBinarySet, hashmapStringSet:
-					updateInsts = append(updateInsts, use)
-				default:
-					unknownUses = true
-				}
-			} else {
-				unknownUses = true
-			}
-		}
-
-		if !unknownUses {
-			// This map can be entirely removed, as it is only created but never
-			// used.
-			for _, inst := range updateInsts {
-				inst.EraseFromParentAsInstruction()
-			}
-			makeInst.EraseFromParentAsInstruction()
-		}
-	}
-}
-
-// Transform runtime.stringToBytes(...) calls into const []byte slices whenever
-// possible. This optimizes the following pattern:
-//     w.Write([]byte("foo"))
-// where Write does not store to the slice.
-func (c *Compiler) OptimizeStringToBytes() {
-	stringToBytes := c.mod.NamedFunction("runtime.stringToBytes")
-	if stringToBytes.IsNil() {
-		// nothing to optimize
-		return
-	}
-
-	for _, call := range getUses(stringToBytes) {
-		strptr := call.Operand(0)
-		strlen := call.Operand(1)
-
-		// strptr is always constant because strings are always constant.
-
-		convertedAllUses := true
-		for _, use := range getUses(call) {
-			nilValue := llvm.Value{}
-			if use.IsAExtractValueInst() == nilValue {
-				convertedAllUses = false
-				continue
-			}
-			switch use.Type().TypeKind() {
-			case llvm.IntegerTypeKind:
-				// A length (len or cap). Propagate the length value.
-				use.ReplaceAllUsesWith(strlen)
-				use.EraseFromParentAsInstruction()
-			case llvm.PointerTypeKind:
-				// The string pointer itself.
-				if !c.isReadOnly(use) {
-					convertedAllUses = false
-					continue
-				}
-				use.ReplaceAllUsesWith(strptr)
-				use.EraseFromParentAsInstruction()
-			default:
-				// should not happen
-				panic("unknown return type of runtime.stringToBytes: " + use.Type().String())
-			}
-		}
-		if convertedAllUses {
-			// Call to runtime.stringToBytes can be eliminated: both the input
-			// and the output is constant.
-			call.EraseFromParentAsInstruction()
-		}
-	}
-}
-
-// Basic escape analysis: translate runtime.alloc calls into alloca
-// instructions.
-func (c *Compiler) OptimizeAllocs() {
-	allocator := c.mod.NamedFunction("runtime.alloc")
-	if allocator.IsNil() {
-		// nothing to optimize
-		return
-	}
-
-	heapallocs := getUses(allocator)
-	for _, heapalloc := range heapallocs {
-		nilValue := llvm.Value{}
-		if heapalloc.Operand(0).IsAConstant() == nilValue {
-			// Do not allocate variable length arrays on the stack.
-			continue
-		}
-		size := heapalloc.Operand(0).ZExtValue()
-		if size > 256 {
-			// The maximum value for a stack allocation.
-			// TODO: tune this, this is just a random value.
-			continue
-		}
-
-		// In general the pattern is:
-		//     %0 = call i8* @runtime.alloc(i32 %size)
-		//     %1 = bitcast i8* %0 to type*
-		//     (use %1 only)
-		// But the bitcast might sometimes be dropped when allocating an *i8.
-		// The 'bitcast' variable below is thus usually a bitcast of the
-		// heapalloc but not always.
-		bitcast := heapalloc // instruction that creates the value
-		if uses := getUses(heapalloc); len(uses) == 1 && uses[0].IsABitCastInst() != nilValue {
-			// getting only bitcast use
-			bitcast = uses[0]
-		}
-		if !c.doesEscape(bitcast) {
-			// Insert alloca in the entry block. Do it here so that mem2reg can
-			// promote it to a SSA value.
-			fn := bitcast.InstructionParent().Parent()
-			c.builder.SetInsertPointBefore(fn.EntryBasicBlock().FirstInstruction())
-			alignment := c.targetData.ABITypeAlignment(c.i8ptrType)
-			sizeInWords := (size + uint64(alignment) - 1) / uint64(alignment)
-			allocaType := llvm.ArrayType(c.ctx.IntType(alignment*8), int(sizeInWords))
-			alloca := c.builder.CreateAlloca(allocaType, "stackalloc.alloca")
-			zero, _ := c.getZeroValue(alloca.Type().ElementType())
-			c.builder.CreateStore(zero, alloca)
-			stackalloc := c.builder.CreateBitCast(alloca, bitcast.Type(), "stackalloc")
-			bitcast.ReplaceAllUsesWith(stackalloc)
-			if heapalloc != bitcast {
-				bitcast.EraseFromParentAsInstruction()
-			}
-			heapalloc.EraseFromParentAsInstruction()
-		}
-	}
-}
-
-// Very basic escape analysis.
-func (c *Compiler) doesEscape(value llvm.Value) bool {
-	uses := getUses(value)
-	for _, use := range uses {
-		nilValue := llvm.Value{}
-		if use.IsAGetElementPtrInst() != nilValue {
-			if c.doesEscape(use) {
-				return true
-			}
-		} else if use.IsABitCastInst() != nilValue {
-			// A bitcast escapes if the casted-to value escapes.
-			if c.doesEscape(use) {
-				return true
-			}
-		} else if use.IsALoadInst() != nilValue {
-			// Load does not escape.
-		} else if use.IsAStoreInst() != nilValue {
-			// Store only escapes when the value is stored to, not when the
-			// value is stored into another value.
-			if use.Operand(0) == value {
-				return true
-			}
-		} else if use.IsACallInst() != nilValue {
-			// Call only escapes when the (pointer) parameter is not marked
-			// "nocapture". This flag means that the parameter does not escape
-			// the give function.
-			if use.CalledValue().IsAFunction() != nilValue {
-				if use.CalledValue().IsDeclaration() {
-					// Kind of dirty: assume external functions don't let
-					// pointers escape.
-					// TODO: introduce //go:noescape that sets the 'nocapture'
-					// flag on each input parameter.
-					continue
-				}
-			}
-			if !c.hasFlag(use, value, "nocapture") {
-				return true
-			}
-		} else {
-			// Unknown instruction, might escape.
-			return true
-		}
-	}
-
-	// does not escape
-	return false
-}
-
-// Check whether the given value (which is of pointer type) is never stored to.
-func (c *Compiler) isReadOnly(value llvm.Value) bool {
-	uses := getUses(value)
-	for _, use := range uses {
-		nilValue := llvm.Value{}
-		if use.IsAGetElementPtrInst() != nilValue {
-			if !c.isReadOnly(use) {
-				return false
-			}
-		} else if use.IsACallInst() != nilValue {
-			if !c.hasFlag(use, value, "readonly") {
-				return false
-			}
-		} else {
-			// Unknown instruction, might not be readonly.
-			return false
-		}
-	}
-	return true
-}
-
-// Check whether all uses of this param as parameter to the call have the given
-// flag. In most cases, there will only be one use but a function could take the
-// same parameter twice, in which case both must have the flag.
-// A flag can be any enum flag, like "readonly".
-func (c *Compiler) hasFlag(call, param llvm.Value, kind string) bool {
-	fn := call.CalledValue()
-	nilValue := llvm.Value{}
-	if fn.IsAFunction() == nilValue {
-		// This is not a function but something else, like a function pointer.
-		return false
-	}
-	kindID := llvm.AttributeKindID(kind)
-	for i := 0; i < fn.ParamsCount(); i++ {
-		if call.Operand(i) != param {
-			// This is not the parameter we're checking.
-			continue
-		}
-		index := i + 1 // param attributes start at 1
-		attr := fn.GetEnumAttributeAtIndex(index, kindID)
-		nilAttribute := llvm.Attribute{}
-		if attr == nilAttribute {
-			// At least one parameter doesn't have the flag (there may be
-			// multiple).
-			return false
-		}
-	}
-	return true
-}
-
-// Return a list of values (actually, instructions) where this value is used as
-// an operand.
-func getUses(value llvm.Value) []llvm.Value {
-	if value.IsNil() {
-		return nil
-	}
-	var uses []llvm.Value
-	use := value.FirstUse()
-	for !use.IsNil() {
-		uses = append(uses, use.User())
-		use = use.NextUse()
-	}
-	return uses
-}

compiler/sizes.go

@@ -10,13 +10,13 @@ import (
 // The original license can be found here:
 //     https://golang.org/LICENSE
 
-type StdSizes struct {
+type stdSizes struct {
 	IntSize  int64
 	PtrSize  int64
 	MaxAlign int64
 }
 
-func (s *StdSizes) Alignof(T types.Type) int64 {
+func (s *stdSizes) Alignof(T types.Type) int64 {
 	// For arrays and structs, alignment is defined in terms
 	// of alignment of the elements and fields, respectively.
 	switch t := T.Underlying().(type) {
@@ -61,7 +61,7 @@ func (s *StdSizes) Alignof(T types.Type) int64 {
 	return a
 }
 
-func (s *StdSizes) Offsetsof(fields []*types.Var) []int64 {
+func (s *stdSizes) Offsetsof(fields []*types.Var) []int64 {
 	offsets := make([]int64, len(fields))
 	var o int64
 	for i, f := range fields {
@@ -89,7 +89,7 @@ var basicSizes = [...]byte{
 	types.Complex128: 16,
 }
 
-func (s *StdSizes) Sizeof(T types.Type) int64 {
+func (s *stdSizes) Sizeof(T types.Type) int64 {
 	switch t := T.Underlying().(type) {
 	case *types.Basic:
 		k := t.Kind()
@@ -107,6 +107,12 @@ func (s *StdSizes) Sizeof(T types.Type) int64 {
 		if k == types.Uintptr {
 			return s.PtrSize
 		}
+		if k == types.UnsafePointer {
+			return s.PtrSize
+		}
+		if k == types.Invalid {
+			return 0 // only relevant when there is a type error somewhere
+		}
 		panic("unknown basic type: " + t.String())
 	case *types.Array:
 		n := t.Len()
@@ -125,15 +131,28 @@ func (s *StdSizes) Sizeof(T types.Type) int64 {
 			return 0
 		}
 		fields := make([]*types.Var, t.NumFields())
+		maxAlign := int64(1)
 		for i := range fields {
-			fields[i] = t.Field(i)
+			field := t.Field(i)
+			fields[i] = field
+			al := s.Alignof(field.Type())
+			if al > maxAlign {
+				maxAlign = al
+			}
 		}
+		// Pick the size that fits this struct and add some alignment. Some
+		// structs have some extra padding at the end which should also be taken
+		// care of:
+		//     struct { int32 n; byte b }
 		offsets := s.Offsetsof(fields)
-		return offsets[n-1] + s.Sizeof(fields[n-1].Type())
+		return align(offsets[n-1]+s.Sizeof(fields[n-1].Type()), maxAlign)
 	case *types.Interface:
 		return s.PtrSize * 2
 	case *types.Pointer:
 		return s.PtrSize
+	case *types.Signature:
+		// Func values in TinyGo are two words in size.
+		return s.PtrSize * 2
 	default:
 		panic("unknown type: " + t.String())
 	}

compiler/symbol.go

@@ -0,0 +1,450 @@
+package compiler
+
+// This file manages symbols, that is, functions and globals. It reads their
+// pragmas, determines the link name, etc.
+
+import (
+	"go/ast"
+	"go/token"
+	"go/types"
+	"strconv"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/loader"
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// functionInfo contains some information about a function or method. In
+// particular, it contains information obtained from pragmas.
+//
+// The linkName value contains a valid link name, even if //go:linkname is not
+// present.
+type functionInfo struct {
+	module     string     // go:wasm-module
+	importName string     // go:linkname, go:export - The name the developer assigns
+	linkName   string     // go:linkname, go:export - The name that we map for the particular module -> importName
+	exported   bool       // go:export, CGo
+	nobounds   bool       // go:nobounds
+	variadic   bool       // go:variadic (CGo only)
+	inline     inlineType // go:inline
+}
+
+type inlineType int
+
+// How much to inline.
+const (
+	// Default behavior. The compiler decides for itself whether any given
+	// function will be inlined. Whether any function is inlined depends on the
+	// optimization level.
+	inlineDefault inlineType = iota
+
+	// Inline hint, just like the C inline keyword (signalled using
+	// //go:inline). The compiler will be more likely to inline this function,
+	// but it is not a guarantee.
+	inlineHint
+
+	// Don't inline, just like the GCC noinline attribute. Signalled using
+	// //go:noinline.
+	inlineNone
+)
+
+// getFunction returns the LLVM function for the given *ssa.Function, creating
+// it if needed. It can later be filled with compilerContext.createFunction().
+func (c *compilerContext) getFunction(fn *ssa.Function) llvm.Value {
+	info := c.getFunctionInfo(fn)
+	llvmFn := c.mod.NamedFunction(info.linkName)
+	if !llvmFn.IsNil() {
+		return llvmFn
+	}
+
+	var retType llvm.Type
+	if fn.Signature.Results() == nil {
+		retType = c.ctx.VoidType()
+	} else if fn.Signature.Results().Len() == 1 {
+		retType = c.getLLVMType(fn.Signature.Results().At(0).Type())
+	} else {
+		results := make([]llvm.Type, 0, fn.Signature.Results().Len())
+		for i := 0; i < fn.Signature.Results().Len(); i++ {
+			results = append(results, c.getLLVMType(fn.Signature.Results().At(i).Type()))
+		}
+		retType = c.ctx.StructType(results, false)
+	}
+
+	var paramInfos []paramInfo
+	for _, param := range getParams(fn.Signature) {
+		paramType := c.getLLVMType(param.Type())
+		paramFragmentInfos := expandFormalParamType(paramType, param.Name(), param.Type())
+		paramInfos = append(paramInfos, paramFragmentInfos...)
+	}
+
+	// Add an extra parameter as the function context. This context is used in
+	// closures and bound methods, but should be optimized away when not used.
+	if !info.exported {
+		paramInfos = append(paramInfos, paramInfo{llvmType: c.i8ptrType, name: "context", flags: 0})
+		paramInfos = append(paramInfos, paramInfo{llvmType: c.i8ptrType, name: "parentHandle", flags: 0})
+	}
+
+	var paramTypes []llvm.Type
+	for _, info := range paramInfos {
+		paramTypes = append(paramTypes, info.llvmType)
+	}
+
+	fnType := llvm.FunctionType(retType, paramTypes, info.variadic)
+	llvmFn = llvm.AddFunction(c.mod, info.linkName, fnType)
+	if strings.HasPrefix(c.Triple, "wasm") {
+		// C functions without prototypes like this:
+		//   void foo();
+		// are actually variadic functions. However, it appears that it has been
+		// decided in WebAssembly that such prototype-less functions are not
+		// allowed in WebAssembly.
+		// In C, this can only happen when there are zero parameters, hence this
+		// check here. For more information:
+		// https://reviews.llvm.org/D48443
+		// https://github.com/WebAssembly/tool-conventions/issues/16
+		if info.variadic && len(fn.Params) == 0 {
+			attr := c.ctx.CreateStringAttribute("no-prototype", "")
+			llvmFn.AddFunctionAttr(attr)
+		}
+	}
+
+	dereferenceableOrNullKind := llvm.AttributeKindID("dereferenceable_or_null")
+	for i, info := range paramInfos {
+		if info.flags&paramIsDeferenceableOrNull == 0 {
+			continue
+		}
+		if info.llvmType.TypeKind() == llvm.PointerTypeKind {
+			el := info.llvmType.ElementType()
+			size := c.targetData.TypeAllocSize(el)
+			if size == 0 {
+				// dereferenceable_or_null(0) appears to be illegal in LLVM.
+				continue
+			}
+			dereferenceableOrNull := c.ctx.CreateEnumAttribute(dereferenceableOrNullKind, size)
+			llvmFn.AddAttributeAtIndex(i+1, dereferenceableOrNull)
+		}
+	}
+
+	// Set a number of function or parameter attributes, depending on the
+	// function. These functions are runtime functions that are known to have
+	// certain attributes that might not be inferred by the compiler.
+	switch info.linkName {
+	case "abort":
+		// On *nix systems, the "abort" functuion in libc is used to handle fatal panics.
+		// Mark it as noreturn so LLVM can optimize away code.
+		llvmFn.AddFunctionAttr(c.ctx.CreateEnumAttribute(llvm.AttributeKindID("noreturn"), 0))
+	case "runtime.alloc":
+		// Tell the optimizer that runtime.alloc is an allocator, meaning that it
+		// returns values that are never null and never alias to an existing value.
+		for _, attrName := range []string{"noalias", "nonnull"} {
+			llvmFn.AddAttributeAtIndex(0, c.ctx.CreateEnumAttribute(llvm.AttributeKindID(attrName), 0))
+		}
+	case "runtime.trackPointer":
+		// This function is necessary for tracking pointers on the stack in a
+		// portable way (see gc_stack_portable.go). Indicate to the optimizer
+		// that the only thing we'll do is read the pointer.
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
+	}
+
+	// External/exported functions may not retain pointer values.
+	// https://golang.org/cmd/cgo/#hdr-Passing_pointers
+	if info.exported {
+		// Set the wasm-import-module attribute if the function's module is set.
+		if info.module != "" {
+
+			// We need to add the wasm-import-module and the wasm-import-name
+			wasmImportModuleAttr := c.ctx.CreateStringAttribute("wasm-import-module", info.module)
+			llvmFn.AddFunctionAttr(wasmImportModuleAttr)
+
+			// Add the Wasm Import Name, if we are a named wasm import
+			if info.importName != "" {
+				wasmImportNameAttr := c.ctx.CreateStringAttribute("wasm-import-name", info.importName)
+				llvmFn.AddFunctionAttr(wasmImportNameAttr)
+			}
+		}
+		nocaptureKind := llvm.AttributeKindID("nocapture")
+		nocapture := c.ctx.CreateEnumAttribute(nocaptureKind, 0)
+		for i, typ := range paramTypes {
+			if typ.TypeKind() == llvm.PointerTypeKind {
+				llvmFn.AddAttributeAtIndex(i+1, nocapture)
+			}
+		}
+	}
+
+	// Synthetic functions are functions that do not appear in the source code,
+	// they are artificially constructed. Usually they are wrapper functions
+	// that are not referenced anywhere except in a SSA call instruction so
+	// should be created right away.
+	// The exception is the package initializer, which does appear in the
+	// *ssa.Package members and so shouldn't be created here.
+	if fn.Synthetic != "" && fn.Synthetic != "package initializer" {
+		irbuilder := c.ctx.NewBuilder()
+		b := newBuilder(c, irbuilder, fn)
+		b.createFunction()
+		irbuilder.Dispose()
+		llvmFn.SetLinkage(llvm.LinkOnceODRLinkage)
+		llvmFn.SetUnnamedAddr(true)
+	}
+
+	return llvmFn
+}
+
+// getFunctionInfo returns information about a function that is not directly
+// present in *ssa.Function, such as the link name and whether it should be
+// exported.
+func (c *compilerContext) getFunctionInfo(f *ssa.Function) functionInfo {
+	info := functionInfo{}
+	if strings.HasPrefix(f.Name(), "C.") {
+		// Created by CGo: such a name cannot be created by regular C code.
+		info.linkName = f.Name()[2:]
+		info.exported = true
+	} else {
+		// Pick the default linkName.
+		info.linkName = f.RelString(nil)
+	}
+	// Check for //go: pragmas, which may change the link name (among others).
+	info.parsePragmas(f)
+	return info
+}
+
+// parsePragmas is used by getFunctionInfo to parse function pragmas such as
+// //export or //go:noinline.
+func (info *functionInfo) parsePragmas(f *ssa.Function) {
+	if f.Syntax() == nil {
+		return
+	}
+	if decl, ok := f.Syntax().(*ast.FuncDecl); ok && decl.Doc != nil {
+
+		// Our importName for a wasm module (if we are compiling to wasm), or llvm link name
+		var importName string
+
+		for _, comment := range decl.Doc.List {
+			text := comment.Text
+			if strings.HasPrefix(text, "//export ") {
+				// Rewrite '//export' to '//go:export' for compatibility with
+				// gc.
+				text = "//go:" + text[2:]
+			}
+			if !strings.HasPrefix(text, "//go:") {
+				continue
+			}
+			parts := strings.Fields(text)
+			switch parts[0] {
+			case "//go:export":
+				if len(parts) != 2 {
+					continue
+				}
+
+				importName = parts[1]
+				info.exported = true
+			case "//go:wasm-module":
+				// Alternative comment for setting the import module.
+				if len(parts) != 2 {
+					continue
+				}
+				info.module = parts[1]
+			case "//go:inline":
+				info.inline = inlineHint
+			case "//go:noinline":
+				info.inline = inlineNone
+			case "//go:linkname":
+				if len(parts) != 3 || parts[1] != f.Name() {
+					continue
+				}
+				// Only enable go:linkname when the package imports "unsafe".
+				// This is a slightly looser requirement than what gc uses: gc
+				// requires the file to import "unsafe", not the package as a
+				// whole.
+				if hasUnsafeImport(f.Pkg.Pkg) {
+					info.linkName = parts[2]
+				}
+			case "//go:nobounds":
+				// Skip bounds checking in this function. Useful for some
+				// runtime functions.
+				// This is somewhat dangerous and thus only imported in packages
+				// that import unsafe.
+				if hasUnsafeImport(f.Pkg.Pkg) {
+					info.nobounds = true
+				}
+			case "//go:variadic":
+				// The //go:variadic pragma is emitted by the CGo preprocessing
+				// pass for C variadic functions. This includes both explicit
+				// (with ...) and implicit (no parameters in signature)
+				// functions.
+				if strings.HasPrefix(f.Name(), "C.") {
+					// This prefix cannot naturally be created, it must have
+					// been created as a result of CGo preprocessing.
+					info.variadic = true
+				}
+			}
+		}
+
+		// Set the importName for our exported function if we have one
+		if importName != "" {
+			if info.module == "" {
+				info.linkName = importName
+			} else {
+				// WebAssembly import
+				info.importName = importName
+			}
+		}
+
+	}
+}
+
+// getParams returns the function parameters, including the receiver at the
+// start. This is an alternative to the Params member of *ssa.Function, which is
+// not yet populated when the package has not yet been built.
+func getParams(sig *types.Signature) []*types.Var {
+	params := []*types.Var{}
+	if sig.Recv() != nil {
+		params = append(params, sig.Recv())
+	}
+	for i := 0; i < sig.Params().Len(); i++ {
+		params = append(params, sig.Params().At(i))
+	}
+	return params
+}
+
+// globalInfo contains some information about a specific global. By default,
+// linkName is equal to .RelString(nil) on a global and extern is false, but for
+// some symbols this is different (due to //go:extern for example).
+type globalInfo struct {
+	linkName string // go:extern
+	extern   bool   // go:extern
+	align    int    // go:align
+}
+
+// loadASTComments loads comments on globals from the AST, for use later in the
+// program. In particular, they are required for //go:extern pragmas on globals.
+func (c *compilerContext) loadASTComments(pkg *loader.Package) {
+	for _, file := range pkg.Files {
+		for _, decl := range file.Decls {
+			switch decl := decl.(type) {
+			case *ast.GenDecl:
+				switch decl.Tok {
+				case token.VAR:
+					if len(decl.Specs) != 1 {
+						continue
+					}
+					for _, spec := range decl.Specs {
+						switch spec := spec.(type) {
+						case *ast.ValueSpec: // decl.Tok == token.VAR
+							for _, name := range spec.Names {
+								id := pkg.Pkg.Path() + "." + name.Name
+								c.astComments[id] = decl.Doc
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+// getGlobal returns a LLVM IR global value for a Go SSA global. It is added to
+// the LLVM IR if it has not been added already.
+func (c *compilerContext) getGlobal(g *ssa.Global) llvm.Value {
+	info := c.getGlobalInfo(g)
+	llvmGlobal := c.mod.NamedGlobal(info.linkName)
+	if llvmGlobal.IsNil() {
+		typ := g.Type().(*types.Pointer).Elem()
+		llvmType := c.getLLVMType(typ)
+		llvmGlobal = llvm.AddGlobal(c.mod, llvmType, info.linkName)
+
+		// Set alignment from the //go:align comment.
+		var alignInBits uint32
+		if info.align < 0 || info.align&(info.align-1) != 0 {
+			// Check for power-of-two (or 0).
+			// See: https://stackoverflow.com/a/108360
+			c.addError(g.Pos(), "global variable alignment must be a positive power of two")
+		} else {
+			// Set the alignment only when it is a power of two.
+			alignInBits = uint32(info.align) ^ uint32(info.align-1)
+			if info.align > c.targetData.ABITypeAlignment(llvmType) {
+				llvmGlobal.SetAlignment(info.align)
+			}
+		}
+
+		if c.Debug && !info.extern {
+			// Add debug info.
+			pos := c.program.Fset.Position(g.Pos())
+			diglobal := c.dibuilder.CreateGlobalVariableExpression(c.difiles[pos.Filename], llvm.DIGlobalVariableExpression{
+				Name:        g.RelString(nil),
+				LinkageName: info.linkName,
+				File:        c.getDIFile(pos.Filename),
+				Line:        pos.Line,
+				Type:        c.getDIType(typ),
+				LocalToUnit: false,
+				Expr:        c.dibuilder.CreateExpression(nil),
+				AlignInBits: alignInBits,
+			})
+			llvmGlobal.AddMetadata(0, diglobal)
+		}
+	}
+	return llvmGlobal
+}
+
+// getGlobalInfo returns some information about a specific global.
+func (c *compilerContext) getGlobalInfo(g *ssa.Global) globalInfo {
+	info := globalInfo{}
+	if strings.HasPrefix(g.Name(), "C.") {
+		// Created by CGo: such a name cannot be created by regular C code.
+		info.linkName = g.Name()[2:]
+		info.extern = true
+	} else {
+		// Pick the default linkName.
+		info.linkName = g.RelString(nil)
+		// Check for //go: pragmas, which may change the link name (among
+		// others).
+		doc := c.astComments[info.linkName]
+		if doc != nil {
+			info.parsePragmas(doc)
+		}
+	}
+	return info
+}
+
+// Parse //go: pragma comments from the source. In particular, it parses the
+// //go:extern pragma on globals.
+func (info *globalInfo) parsePragmas(doc *ast.CommentGroup) {
+	for _, comment := range doc.List {
+		if !strings.HasPrefix(comment.Text, "//go:") {
+			continue
+		}
+		parts := strings.Fields(comment.Text)
+		switch parts[0] {
+		case "//go:extern":
+			info.extern = true
+			if len(parts) == 2 {
+				info.linkName = parts[1]
+			}
+		case "//go:align":
+			align, err := strconv.Atoi(parts[1])
+			if err == nil {
+				info.align = align
+			}
+		}
+	}
+}
+
+// Get all methods of a type.
+func getAllMethods(prog *ssa.Program, typ types.Type) []*types.Selection {
+	ms := prog.MethodSets.MethodSet(typ)
+	methods := make([]*types.Selection, ms.Len())
+	for i := 0; i < ms.Len(); i++ {
+		methods[i] = ms.At(i)
+	}
+	return methods
+}
+
+// Return true if this package imports "unsafe", false otherwise.
+func hasUnsafeImport(pkg *types.Package) bool {
+	for _, imp := range pkg.Imports() {
+		if imp == types.Unsafe {
+			return true
+		}
+	}
+	return false
+}

compiler/syscall.go

@@ -0,0 +1,192 @@
+package compiler
+
+// This file implements the syscall.Syscall and syscall.Syscall6 instructions as
+// compiler builtins.
+
+import (
+	"strconv"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createSyscall emits an inline system call instruction, depending on the
+// target OS/arch.
+func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
+	num := b.getValue(call.Args[0])
+	var syscallResult llvm.Value
+	switch {
+	case b.GOARCH == "amd64":
+		if b.GOOS == "darwin" {
+			// Darwin adds this magic number to system call numbers:
+			//
+			// > Syscall classes for 64-bit system call entry.
+			// > For 64-bit users, the 32-bit syscall number is partitioned
+			// > with the high-order bits representing the class and low-order
+			// > bits being the syscall number within that class.
+			// > The high-order 32-bits of the 64-bit syscall number are unused.
+			// > All system classes enter the kernel via the syscall instruction.
+			//
+			// Source: https://opensource.apple.com/source/xnu/xnu-792.13.8/osfmk/mach/i386/syscall_sw.h
+			num = b.CreateOr(num, llvm.ConstInt(b.uintptrType, 0x2000000, false), "")
+		}
+		// Sources:
+		//   https://stackoverflow.com/a/2538212
+		//   https://en.wikibooks.org/wiki/X86_Assembly/Interfacing_with_Linux#syscall
+		args := []llvm.Value{num}
+		argTypes := []llvm.Type{b.uintptrType}
+		// Constraints will look something like:
+		//   "={rax},0,{rdi},{rsi},{rdx},{r10},{r8},{r9},~{rcx},~{r11}"
+		constraints := "={rax},0"
+		for i, arg := range call.Args[1:] {
+			constraints += "," + [...]string{
+				"{rdi}",
+				"{rsi}",
+				"{rdx}",
+				"{r10}",
+				"{r8}",
+				"{r9}",
+				"{r11}",
+				"{r12}",
+				"{r13}",
+			}[i]
+			llvmValue := b.getValue(arg)
+			args = append(args, llvmValue)
+			argTypes = append(argTypes, llvmValue.Type())
+		}
+		constraints += ",~{rcx},~{r11}"
+		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+		target := llvm.InlineAsm(fnType, "syscall", constraints, true, false, llvm.InlineAsmDialectIntel)
+		syscallResult = b.CreateCall(target, args, "")
+	case b.GOARCH == "386" && b.GOOS == "linux":
+		// Sources:
+		//   syscall(2) man page
+		//   https://stackoverflow.com/a/2538212
+		//   https://en.wikibooks.org/wiki/X86_Assembly/Interfacing_with_Linux#int_0x80
+		args := []llvm.Value{num}
+		argTypes := []llvm.Type{b.uintptrType}
+		// Constraints will look something like:
+		//   "={eax},0,{ebx},{ecx},{edx},{esi},{edi},{ebp}"
+		constraints := "={eax},0"
+		for i, arg := range call.Args[1:] {
+			constraints += "," + [...]string{
+				"{ebx}",
+				"{ecx}",
+				"{edx}",
+				"{esi}",
+				"{edi}",
+				"{ebp}",
+			}[i]
+			llvmValue := b.getValue(arg)
+			args = append(args, llvmValue)
+			argTypes = append(argTypes, llvmValue.Type())
+		}
+		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+		target := llvm.InlineAsm(fnType, "int 0x80", constraints, true, false, llvm.InlineAsmDialectIntel)
+		syscallResult = b.CreateCall(target, args, "")
+	case b.GOARCH == "arm" && b.GOOS == "linux":
+		// Implement the EABI system call convention for Linux.
+		// Source: syscall(2) man page.
+		args := []llvm.Value{}
+		argTypes := []llvm.Type{}
+		// Constraints will look something like:
+		//   ={r0},0,{r1},{r2},{r7},~{r3}
+		constraints := "={r0}"
+		for i, arg := range call.Args[1:] {
+			constraints += "," + [...]string{
+				"0", // tie to output
+				"{r1}",
+				"{r2}",
+				"{r3}",
+				"{r4}",
+				"{r5}",
+				"{r6}",
+			}[i]
+			llvmValue := b.getValue(arg)
+			args = append(args, llvmValue)
+			argTypes = append(argTypes, llvmValue.Type())
+		}
+		args = append(args, num)
+		argTypes = append(argTypes, b.uintptrType)
+		constraints += ",{r7}" // syscall number
+		for i := len(call.Args) - 1; i < 4; i++ {
+			// r0-r3 get clobbered after the syscall returns
+			constraints += ",~{r" + strconv.Itoa(i) + "}"
+		}
+		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+		target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0)
+		syscallResult = b.CreateCall(target, args, "")
+	case b.GOARCH == "arm64" && b.GOOS == "linux":
+		// Source: syscall(2) man page.
+		args := []llvm.Value{}
+		argTypes := []llvm.Type{}
+		// Constraints will look something like:
+		//   ={x0},0,{x1},{x2},{x8},~{x3},~{x4},~{x5},~{x6},~{x7},~{x16},~{x17}
+		constraints := "={x0}"
+		for i, arg := range call.Args[1:] {
+			constraints += "," + [...]string{
+				"0", // tie to output
+				"{x1}",
+				"{x2}",
+				"{x3}",
+				"{x4}",
+				"{x5}",
+			}[i]
+			llvmValue := b.getValue(arg)
+			args = append(args, llvmValue)
+			argTypes = append(argTypes, llvmValue.Type())
+		}
+		args = append(args, num)
+		argTypes = append(argTypes, b.uintptrType)
+		constraints += ",{x8}" // syscall number
+		for i := len(call.Args) - 1; i < 8; i++ {
+			// x0-x7 may get clobbered during the syscall following the aarch64
+			// calling convention.
+			constraints += ",~{x" + strconv.Itoa(i) + "}"
+		}
+		constraints += ",~{x16},~{x17}" // scratch registers
+		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
+		target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0)
+		syscallResult = b.CreateCall(target, args, "")
+	default:
+		return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS+"/"+b.GOARCH)
+	}
+	switch b.GOOS {
+	case "linux", "freebsd":
+		// Return values: r0, r1 uintptr, err Errno
+		// Pseudocode:
+		//     var err uintptr
+		//     if syscallResult < 0 && syscallResult > -4096 {
+		//         err = -syscallResult
+		//     }
+		//     return syscallResult, 0, err
+		zero := llvm.ConstInt(b.uintptrType, 0, false)
+		inrange1 := b.CreateICmp(llvm.IntSLT, syscallResult, llvm.ConstInt(b.uintptrType, 0, false), "")
+		inrange2 := b.CreateICmp(llvm.IntSGT, syscallResult, llvm.ConstInt(b.uintptrType, 0xfffffffffffff000, true), "") // -4096
+		hasError := b.CreateAnd(inrange1, inrange2, "")
+		errResult := b.CreateSelect(hasError, b.CreateSub(zero, syscallResult, ""), zero, "syscallError")
+		retval := llvm.Undef(b.ctx.StructType([]llvm.Type{b.uintptrType, b.uintptrType, b.uintptrType}, false))
+		retval = b.CreateInsertValue(retval, syscallResult, 0, "")
+		retval = b.CreateInsertValue(retval, zero, 1, "")
+		retval = b.CreateInsertValue(retval, errResult, 2, "")
+		return retval, nil
+	case "darwin":
+		// Return values: r0, r1 uintptr, err Errno
+		// Pseudocode:
+		//     var err uintptr
+		//     if syscallResult != 0 {
+		//         err = syscallResult
+		//     }
+		//     return syscallResult, 0, err
+		zero := llvm.ConstInt(b.uintptrType, 0, false)
+		hasError := b.CreateICmp(llvm.IntNE, syscallResult, llvm.ConstInt(b.uintptrType, 0, false), "")
+		errResult := b.CreateSelect(hasError, syscallResult, zero, "syscallError")
+		retval := llvm.Undef(b.ctx.StructType([]llvm.Type{b.uintptrType, b.uintptrType, b.uintptrType}, false))
+		retval = b.CreateInsertValue(retval, syscallResult, 0, "")
+		retval = b.CreateInsertValue(retval, zero, 1, "")
+		retval = b.CreateInsertValue(retval, errResult, 2, "")
+		return retval, nil
+	default:
+		return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS+"/"+b.GOARCH)
+	}
+}

compiler/testdata/basic.go

@@ -0,0 +1,57 @@
+package main
+
+// Basic tests that don't need to be split into a separate file.
+
+func addInt(x, y int) int {
+	return x + y
+}
+
+func equalInt(x, y int) bool {
+	return x == y
+}
+
+func floatEQ(x, y float32) bool {
+	return x == y
+}
+
+func floatNE(x, y float32) bool {
+	return x != y
+}
+
+func floatLower(x, y float32) bool {
+	return x < y
+}
+
+func floatLowerEqual(x, y float32) bool {
+	return x <= y
+}
+
+func floatGreater(x, y float32) bool {
+	return x > y
+}
+
+func floatGreaterEqual(x, y float32) bool {
+	return x >= y
+}
+
+func complexReal(x complex64) float32 {
+	return real(x)
+}
+
+func complexImag(x complex64) float32 {
+	return imag(x)
+}
+
+func complexAdd(x, y complex64) complex64 {
+	return x + y
+}
+
+func complexSub(x, y complex64) complex64 {
+	return x - y
+}
+
+func complexMul(x, y complex64) complex64 {
+	return x * y
+}
+
+// TODO: complexDiv (requires runtime call)

compiler/testdata/basic.ll

@@ -0,0 +1,100 @@
+; ModuleID = 'basic.go'
+source_filename = "basic.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret void
+}
+
+define hidden i32 @main.addInt(i32 %x, i32 %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = add i32 %x, %y
+  ret i32 %0
+}
+
+define hidden i1 @main.equalInt(i32 %x, i32 %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = icmp eq i32 %x, %y
+  ret i1 %0
+}
+
+define hidden i1 @main.floatEQ(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fcmp oeq float %x, %y
+  ret i1 %0
+}
+
+define hidden i1 @main.floatNE(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fcmp une float %x, %y
+  ret i1 %0
+}
+
+define hidden i1 @main.floatLower(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fcmp olt float %x, %y
+  ret i1 %0
+}
+
+define hidden i1 @main.floatLowerEqual(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fcmp ole float %x, %y
+  ret i1 %0
+}
+
+define hidden i1 @main.floatGreater(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fcmp ogt float %x, %y
+  ret i1 %0
+}
+
+define hidden i1 @main.floatGreaterEqual(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fcmp oge float %x, %y
+  ret i1 %0
+}
+
+define hidden float @main.complexReal(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret float %x.r
+}
+
+define hidden float @main.complexImag(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret float %x.i
+}
+
+define hidden { float, float } @main.complexAdd(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fadd float %x.r, %y.r
+  %1 = fadd float %x.i, %y.i
+  %2 = insertvalue { float, float } undef, float %0, 0
+  %3 = insertvalue { float, float } %2, float %1, 1
+  ret { float, float } %3
+}
+
+define hidden { float, float } @main.complexSub(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fsub float %x.r, %y.r
+  %1 = fsub float %x.i, %y.i
+  %2 = insertvalue { float, float } undef, float %0, 0
+  %3 = insertvalue { float, float } %2, float %1, 1
+  ret { float, float } %3
+}
+
+define hidden { float, float } @main.complexMul(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = fmul float %x.r, %y.r
+  %1 = fmul float %x.i, %y.i
+  %2 = fsub float %0, %1
+  %3 = fmul float %x.r, %y.i
+  %4 = fmul float %x.i, %y.r
+  %5 = fadd float %3, %4
+  %6 = insertvalue { float, float } undef, float %2, 0
+  %7 = insertvalue { float, float } %6, float %5, 1
+  ret { float, float } %7
+}

compiler/testdata/float.go

@@ -0,0 +1,39 @@
+package main
+
+// Test converting floats to ints.
+
+func f32tou32(v float32) uint32 {
+	return uint32(v)
+}
+
+func maxu32f() float32 {
+	return float32(^uint32(0))
+}
+
+func maxu32tof32() uint32 {
+	f := float32(^uint32(0))
+	return uint32(f)
+}
+
+func inftoi32() (uint32, uint32, int32, int32) {
+	inf := 1.0
+	inf /= 0.0
+
+	return uint32(inf), uint32(-inf), int32(inf), int32(-inf)
+}
+
+func u32tof32tou32(v uint32) uint32 {
+	return uint32(float32(v))
+}
+
+func f32tou32tof32(v float32) float32 {
+	return float32(uint32(v))
+}
+
+func f32tou8(v float32) uint8 {
+	return uint8(v)
+}
+
+func f32toi8(v float32) int8 {
+	return int8(v)
+}

compiler/testdata/float.ll

@@ -0,0 +1,82 @@
+; ModuleID = 'float.go'
+source_filename = "float.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret void
+}
+
+define hidden i32 @main.f32tou32(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %positive = fcmp oge float %v, 0.000000e+00
+  %withinmax = fcmp ole float %v, 0x41EFFFFFC0000000
+  %inbounds = and i1 %positive, %withinmax
+  %saturated = sext i1 %positive to i32
+  %normal = fptoui float %v to i32
+  %0 = select i1 %inbounds, i32 %normal, i32 %saturated
+  ret i32 %0
+}
+
+define hidden float @main.maxu32f(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret float 0x41F0000000000000
+}
+
+define hidden i32 @main.maxu32tof32(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret i32 -1
+}
+
+define hidden { i32, i32, i32, i32 } @main.inftoi32(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret { i32, i32, i32, i32 } { i32 -1, i32 0, i32 2147483647, i32 -2147483648 }
+}
+
+define hidden i32 @main.u32tof32tou32(i32 %v, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = uitofp i32 %v to float
+  %withinmax = fcmp ole float %0, 0x41EFFFFFC0000000
+  %normal = fptoui float %0 to i32
+  %1 = select i1 %withinmax, i32 %normal, i32 -1
+  ret i32 %1
+}
+
+define hidden float @main.f32tou32tof32(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %positive = fcmp oge float %v, 0.000000e+00
+  %withinmax = fcmp ole float %v, 0x41EFFFFFC0000000
+  %inbounds = and i1 %positive, %withinmax
+  %saturated = sext i1 %positive to i32
+  %normal = fptoui float %v to i32
+  %0 = select i1 %inbounds, i32 %normal, i32 %saturated
+  %1 = uitofp i32 %0 to float
+  ret float %1
+}
+
+define hidden i8 @main.f32tou8(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %positive = fcmp oge float %v, 0.000000e+00
+  %withinmax = fcmp ole float %v, 2.550000e+02
+  %inbounds = and i1 %positive, %withinmax
+  %saturated = sext i1 %positive to i8
+  %normal = fptoui float %v to i8
+  %0 = select i1 %inbounds, i8 %normal, i8 %saturated
+  ret i8 %0
+}
+
+define hidden i8 @main.f32toi8(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %abovemin = fcmp oge float %v, -1.280000e+02
+  %belowmax = fcmp ole float %v, 1.270000e+02
+  %inbounds = and i1 %abovemin, %belowmax
+  %saturated = select i1 %abovemin, i8 127, i8 -128
+  %isnan = fcmp uno float %v, 0.000000e+00
+  %remapped = select i1 %isnan, i8 0, i8 %saturated
+  %normal = fptosi float %v to i8
+  %0 = select i1 %inbounds, i8 %normal, i8 %remapped
+  ret i8 %0
+}

compiler/testdata/interface.go

@@ -0,0 +1,54 @@
+// This file tests interface types and interface builtins.
+
+package main
+
+// Test interface construction.
+
+func simpleType() interface{} {
+	return 0
+}
+
+func pointerType() interface{} {
+	// Pointers have an element type, in this case int.
+	var v *int
+	return v
+}
+
+func interfaceType() interface{} {
+	// Interfaces can exist in interfaces, but only indirectly (through
+	// pointers).
+	var v *error
+	return v
+}
+
+func anonymousInterfaceType() interface{} {
+	var v *interface {
+		String() string
+	}
+	return v
+}
+
+// Test interface builtins.
+
+func isInt(itf interface{}) bool {
+	_, ok := itf.(int)
+	return ok
+}
+
+func isError(itf interface{}) bool {
+	// Interface assert on (builtin) named interface type.
+	_, ok := itf.(error)
+	return ok
+}
+
+func isStringer(itf interface{}) bool {
+	// Interface assert on anonymous interface type.
+	_, ok := itf.(interface {
+		String() string
+	})
+	return ok
+}
+
+func callErrorMethod(itf error) string {
+	return itf.Error()
+}

compiler/testdata/interface.ll

@@ -0,0 +1,100 @@
+; ModuleID = 'interface.go'
+source_filename = "interface.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+%runtime.typecodeID = type { %runtime.typecodeID*, i32, %runtime.interfaceMethodInfo* }
+%runtime.interfaceMethodInfo = type { i8*, i32 }
+%runtime._interface = type { i32, i8* }
+%runtime._string = type { i8*, i32 }
+
+@"reflect/types.type:basic:int" = linkonce_odr constant %runtime.typecodeID zeroinitializer
+@"reflect/types.type:pointer:basic:int" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i32 0, %runtime.interfaceMethodInfo* null }
+@"reflect/types.type:pointer:named:error" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:named:error", i32 0, %runtime.interfaceMethodInfo* null }
+@"reflect/types.type:named:error" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:interface:{Error:func:{}{basic:string}}", i32 0, %runtime.interfaceMethodInfo* null }
+@"reflect/types.type:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* bitcast ([1 x i8*]* @"reflect/types.interface:interface{Error() string}$interface" to %runtime.typecodeID*), i32 0, %runtime.interfaceMethodInfo* null }
+@"func Error() string" = external constant i8
+@"reflect/types.interface:interface{Error() string}$interface" = linkonce_odr constant [1 x i8*] [i8* @"func Error() string"]
+@"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:interface:{String:func:{}{basic:string}}", i32 0, %runtime.interfaceMethodInfo* null }
+@"reflect/types.type:interface:{String:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* bitcast ([1 x i8*]* @"reflect/types.interface:interface{String() string}$interface" to %runtime.typecodeID*), i32 0, %runtime.interfaceMethodInfo* null }
+@"func String() string" = external constant i8
+@"reflect/types.interface:interface{String() string}$interface" = linkonce_odr constant [1 x i8*] [i8* @"func String() string"]
+@"reflect/types.type:basic:int$id" = external constant i8
+@"error$interface" = linkonce_odr constant [1 x i8*] [i8* @"func Error() string"]
+
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret void
+}
+
+define hidden %runtime._interface @main.simpleType(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:basic:int" to i32), i8* null }
+}
+
+define hidden %runtime._interface @main.pointerType(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:pointer:basic:int" to i32), i8* null }
+}
+
+define hidden %runtime._interface @main.interfaceType(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:pointer:named:error" to i32), i8* null }
+}
+
+define hidden %runtime._interface @main.anonymousInterfaceType(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" to i32), i8* null }
+}
+
+define hidden i1 @main.isInt(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %typecode = call i1 @runtime.typeAssert(i32 %itf.typecode, i8* nonnull @"reflect/types.type:basic:int$id", i8* undef, i8* null)
+  br i1 %typecode, label %typeassert.ok, label %typeassert.next
+
+typeassert.ok:                                    ; preds = %entry
+  br label %typeassert.next
+
+typeassert.next:                                  ; preds = %typeassert.ok, %entry
+  ret i1 %typecode
+}
+
+declare i1 @runtime.typeAssert(i32, i8* dereferenceable_or_null(1), i8*, i8*)
+
+define hidden i1 @main.isError(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = call i1 @runtime.interfaceImplements(i32 %itf.typecode, i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"error$interface", i32 0, i32 0), i8* undef, i8* null)
+  br i1 %0, label %typeassert.ok, label %typeassert.next
+
+typeassert.ok:                                    ; preds = %entry
+  br label %typeassert.next
+
+typeassert.next:                                  ; preds = %typeassert.ok, %entry
+  ret i1 %0
+}
+
+declare i1 @runtime.interfaceImplements(i32, i8** dereferenceable_or_null(4), i8*, i8*)
+
+define hidden i1 @main.isStringer(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = call i1 @runtime.interfaceImplements(i32 %itf.typecode, i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"reflect/types.interface:interface{String() string}$interface", i32 0, i32 0), i8* undef, i8* null)
+  br i1 %0, label %typeassert.ok, label %typeassert.next
+
+typeassert.ok:                                    ; preds = %entry
+  br label %typeassert.next
+
+typeassert.next:                                  ; preds = %typeassert.ok, %entry
+  ret i1 %0
+}
+
+define hidden %runtime._string @main.callErrorMethod(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %invoke.func = call i32 @runtime.interfaceMethod(i32 %itf.typecode, i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"error$interface", i32 0, i32 0), i8* nonnull @"func Error() string", i8* undef, i8* null)
+  %invoke.func.cast = inttoptr i32 %invoke.func to %runtime._string (i8*, i8*, i8*)*
+  %0 = call %runtime._string %invoke.func.cast(i8* %itf.value, i8* undef, i8* undef)
+  ret %runtime._string %0
+}
+
+declare i32 @runtime.interfaceMethod(i32, i8** dereferenceable_or_null(4), i8* dereferenceable_or_null(1), i8*, i8*)

compiler/testdata/pointer.go

@@ -0,0 +1,41 @@
+package main
+
+// This file tests various operations on pointers, such as pointer arithmetic
+// and dereferencing pointers.
+
+import "unsafe"
+
+// Dereference pointers.
+
+func pointerDerefZero(x *[0]int) [0]int {
+	return *x // This is a no-op, there is nothing to load.
+}
+
+// Unsafe pointer casts, they are sometimes a no-op.
+
+func pointerCastFromUnsafe(x unsafe.Pointer) *int {
+	return (*int)(x)
+}
+
+func pointerCastToUnsafe(x *int) unsafe.Pointer {
+	return unsafe.Pointer(x)
+}
+
+func pointerCastToUnsafeNoop(x *byte) unsafe.Pointer {
+	return unsafe.Pointer(x)
+}
+
+// The compiler has support for a few special cast+add patterns that are
+// transformed into a single GEP.
+
+func pointerUnsafeGEPFixedOffset(ptr *byte) *byte {
+	return (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + 10))
+}
+
+func pointerUnsafeGEPByteOffset(ptr *byte, offset uintptr) *byte {
+	return (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + offset))
+}
+
+func pointerUnsafeGEPIntOffset(ptr *int32, offset uintptr) *int32 {
+	return (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + offset*4))
+}

compiler/testdata/pointer.ll

@@ -0,0 +1,51 @@
+; ModuleID = 'pointer.go'
+source_filename = "pointer.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret void
+}
+
+define hidden [0 x i32] @main.pointerDerefZero([0 x i32]* %x, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret [0 x i32] zeroinitializer
+}
+
+define hidden i32* @main.pointerCastFromUnsafe(i8* %x, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = bitcast i8* %x to i32*
+  ret i32* %0
+}
+
+define hidden i8* @main.pointerCastToUnsafe(i32* dereferenceable_or_null(4) %x, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = bitcast i32* %x to i8*
+  ret i8* %0
+}
+
+define hidden i8* @main.pointerCastToUnsafeNoop(i8* dereferenceable_or_null(1) %x, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret i8* %x
+}
+
+define hidden i8* @main.pointerUnsafeGEPFixedOffset(i8* dereferenceable_or_null(1) %ptr, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = getelementptr inbounds i8, i8* %ptr, i32 10
+  ret i8* %0
+}
+
+define hidden i8* @main.pointerUnsafeGEPByteOffset(i8* dereferenceable_or_null(1) %ptr, i32 %offset, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = getelementptr inbounds i8, i8* %ptr, i32 %offset
+  ret i8* %0
+}
+
+define hidden i32* @main.pointerUnsafeGEPIntOffset(i32* dereferenceable_or_null(4) %ptr, i32 %offset, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %0 = getelementptr i32, i32* %ptr, i32 %offset
+  ret i32* %0
+}

compiler/testdata/slice.go

@@ -0,0 +1,25 @@
+package main
+
+func sliceLen(ints []int) int {
+	return len(ints)
+}
+
+func sliceCap(ints []int) int {
+	return cap(ints)
+}
+
+func sliceElement(ints []int, index int) int {
+	return ints[index]
+}
+
+func sliceAppendValues(ints []int) []int {
+	return append(ints, 1, 2, 3)
+}
+
+func sliceAppendSlice(ints, added []int) []int {
+	return append(ints, added...)
+}
+
+func sliceCopy(dst, src []int) int {
+	return copy(dst, src)
+}

compiler/testdata/slice.ll

@@ -0,0 +1,88 @@
+; ModuleID = 'slice.go'
+source_filename = "slice.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret void
+}
+
+define hidden i32 @main.sliceLen(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret i32 %ints.len
+}
+
+define hidden i32 @main.sliceCap(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  ret i32 %ints.cap
+}
+
+define hidden i32 @main.sliceElement(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i32 %index, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %.not = icmp ult i32 %index, %ints.len
+  br i1 %.not, label %lookup.next, label %lookup.throw
+
+lookup.throw:                                     ; preds = %entry
+  call void @runtime.lookupPanic(i8* undef, i8* null)
+  unreachable
+
+lookup.next:                                      ; preds = %entry
+  %0 = getelementptr inbounds i32, i32* %ints.data, i32 %index
+  %1 = load i32, i32* %0, align 4
+  ret i32 %1
+}
+
+declare void @runtime.lookupPanic(i8*, i8*)
+
+define hidden { i32*, i32, i32 } @main.sliceAppendValues(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %varargs = call i8* @runtime.alloc(i32 12, i8* undef, i8* null)
+  %0 = bitcast i8* %varargs to i32*
+  store i32 1, i32* %0, align 4
+  %1 = getelementptr inbounds i8, i8* %varargs, i32 4
+  %2 = bitcast i8* %1 to i32*
+  store i32 2, i32* %2, align 4
+  %3 = getelementptr inbounds i8, i8* %varargs, i32 8
+  %4 = bitcast i8* %3 to i32*
+  store i32 3, i32* %4, align 4
+  %append.srcPtr = bitcast i32* %ints.data to i8*
+  %append.new = call { i8*, i32, i32 } @runtime.sliceAppend(i8* %append.srcPtr, i8* nonnull %varargs, i32 %ints.len, i32 %ints.cap, i32 3, i32 4, i8* undef, i8* null)
+  %append.newPtr = extractvalue { i8*, i32, i32 } %append.new, 0
+  %append.newBuf = bitcast i8* %append.newPtr to i32*
+  %append.newLen = extractvalue { i8*, i32, i32 } %append.new, 1
+  %append.newCap = extractvalue { i8*, i32, i32 } %append.new, 2
+  %5 = insertvalue { i32*, i32, i32 } undef, i32* %append.newBuf, 0
+  %6 = insertvalue { i32*, i32, i32 } %5, i32 %append.newLen, 1
+  %7 = insertvalue { i32*, i32, i32 } %6, i32 %append.newCap, 2
+  ret { i32*, i32, i32 } %7
+}
+
+declare { i8*, i32, i32 } @runtime.sliceAppend(i8*, i8*, i32, i32, i32, i32, i8*, i8*)
+
+define hidden { i32*, i32, i32 } @main.sliceAppendSlice(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i32* %added.data, i32 %added.len, i32 %added.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %append.srcPtr = bitcast i32* %ints.data to i8*
+  %append.srcPtr1 = bitcast i32* %added.data to i8*
+  %append.new = call { i8*, i32, i32 } @runtime.sliceAppend(i8* %append.srcPtr, i8* %append.srcPtr1, i32 %ints.len, i32 %ints.cap, i32 %added.len, i32 4, i8* undef, i8* null)
+  %append.newPtr = extractvalue { i8*, i32, i32 } %append.new, 0
+  %append.newBuf = bitcast i8* %append.newPtr to i32*
+  %append.newLen = extractvalue { i8*, i32, i32 } %append.new, 1
+  %append.newCap = extractvalue { i8*, i32, i32 } %append.new, 2
+  %0 = insertvalue { i32*, i32, i32 } undef, i32* %append.newBuf, 0
+  %1 = insertvalue { i32*, i32, i32 } %0, i32 %append.newLen, 1
+  %2 = insertvalue { i32*, i32, i32 } %1, i32 %append.newCap, 2
+  ret { i32*, i32, i32 } %2
+}
+
+define hidden i32 @main.sliceCopy(i32* %dst.data, i32 %dst.len, i32 %dst.cap, i32* %src.data, i32 %src.len, i32 %src.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %copy.dstPtr = bitcast i32* %dst.data to i8*
+  %copy.srcPtr = bitcast i32* %src.data to i8*
+  %copy.n = call i32 @runtime.sliceCopy(i8* %copy.dstPtr, i8* %copy.srcPtr, i32 %dst.len, i32 %src.len, i32 4, i8* undef, i8* null)
+  ret i32 %copy.n
+}
+
+declare i32 @runtime.sliceCopy(i8*, i8*, i32, i32, i32, i8*, i8*)